# Merioneth (UK Parliament constituency)

Merioneth, sometimes called Merionethshire, was a constituency in North Wales established in 1542, which returned one Member of Parliament (MP) to the House of Commons of the English Parliament, and later to the Parliament of Great Britain and of the United Kingdom. It was abolished for the 1983 general election, when it was largely replaced by the new constituency of Meirionnydd Nant Conwy.

## Overview
### Boundaries

The constituency consisted of the historic county of Merionethshire. Merioneth was always an almost entirely rural constituency, rocky and mountainous with grazing the only useful agricultural activity that could be pursued; quarrying was its other main economic mainstay. It was also a strongly Welsh-speaking area (a parliamentary paper in 1904 listed that just 6.2% of the population could only speak English, lower than in any other county in Wales), and by the 19th century was a stronghold of non-conformist religion.

### Establishment

Like the rest of Wales, Merioneth was given the right to representation by the Laws in Wales Acts 1535-1542, and first returned an MP to the Parliament of 1542; however, unlike all the other Welsh counties, Merioneth had no towns sufficiently important in the 16th century to merit borough status, so the county MP was its only representative. The MP was chosen by the first past the post electoral system – when there was a contest at all, which was almost unheard of before the second half of the 19th century.

### Franchise and political influences before the Reform Act

As in other county constituencies, the franchise until 1832 was defined by the Forty Shilling Freeholder Act, which gave the right to vote to every man who possessed freehold property within the county valued at £2 or more per year for the purposes of land tax; it was not necessary for the freeholder to occupy his land, nor even in later years to be resident in the county at all. Nevertheless, the electorate was small, probably only a few hundred, though the lack of contested elections make it impossible to be sure: at the 1774 election, the only one to go to a poll in the 18th century, exactly 600 votes were cast. By way of comparison, the population at the time of the 1831 census was about 34,500.
For more than a century before the Reform Act, Merioneth's representation was almost entirely monopolised by the Vaughan family of Corsygedol – they and the Wynns of Wynnstay, who supported them, were the two leading families of the county and the expense of a contested election was presumably seen as futile by any potential opposition candidates. When a magnate from outside the county, The Earl of Powis, did intervene in 1774, his candidate was roundly defeated. Since the Vaughans were not aligned with any of the great aristocratic interests of the rest of Wales, and were generally regarded as maintaining their independence, there was little partisan interest in dislodging them.

### Survival as a constituency with low population

Although the franchise was somewhat extended under the Great Reform Act, Merioneth's registered electorate at the first post-Reform election was only 580. However, it seems that this considerably under-represented those who were eligible, and more voters could be induced to register by vigorous campaigning. The Liberation Society, a body aiming to maximise the non-conformist vote to achieve disestablishment of the church, was active in Merioneth and a number of other Welsh counties in the 1850s and 1860s, and between the elections of 1859 and 1865 Merioneth's electorate rose by 50%, from 1,091 to 1,527. But there was also a dramatic rise in the electorate between 1835 and 1837 (from 698 to 1,336), which is less easy to explain. Nevertheless, even with these occasional peaks, Merioneth was a small constituency by Welsh – let alone English – standards.
By the time of the 1911 census, the population of Merioneth was 46,849, and in other circumstances it would have been too small to survive as a separate constituency, but the physical geography meant that the inconvenience which would be caused to voters and MPs alike by combining it with a neighbouring county outweighed any arguments for mathematical equality of representation. In 1929, the first election at which all adult men and women had the vote, Merioneth's electorate was under 29,000, and it had fallen even further (to 27,619) by the time of the final (1979) election before the constituency was abolished, even with the extension of the franchise to 18- to 21-year-olds in the 1960s.

### Political character after the 1860s

The gentry returned unopposed as MPs in Merioneth's deferential days had usually been Conservatives. At the 1850 general election, the sitting member, W.W.E. Wynne of Peniarth, was challenged by the Liberal, David Williams. In an election characterised by allegations of coercion against the nonconformist tenantry, Wynne held the seat by a small majority. In 1865, Wynne stood down, and was succeeded as Conservative candidate by his son, W.R.M. Wynne. Against some expectations, he held the seat with a slightly reduced majority, and this was attributed by Ieuan Gwynedd Jones to 'a sense of terror' that had struck the mainly nonconformist tenant farmers. In 1868, following the extension of the franchise, Wynne withdrew rather than face another contest which he was likely to lose. With the introduction of the secret ballot, Merioneth became one of the safest Liberal seats in Wales – mainly the effect of the high number of workers in the slate and limestone quarries round Ffestiniog and Corwen. With the foundation of the Labour Party, the seat became less safe, but the Liberals held it through the first half of the 20th century, losing it to Labour, when Emrys Roberts was defeated by T.W. Jones. The Liberals remained the main challengers until the 1960s. However, with the emergence of Plaid Cymru as a political force, Merioneth was natural territory for the nationalists: they overtook the Liberals for second place behind Labour in 1970, and then Dafydd Elis-Thomas captured the seat at the February 1974 election, one of the first two seats the party had won at a general election. They retained it comfortably in October 1974 and 1979.

### Abolition

The constituency was finally abolished with effect from the 1983 general election, when the alignment of constituency boundaries with the revised Welsh county boundaries necessitated a change. The Boundary Commission's original proposals would have united Merioneth with English-speaking Conwy on the North Wales coast, and would almost certainly have extinguished Plaid Cymru's chances of holding the seat, but after a public enquiry much more modest changes were adopted. The bulk of the electorate formed the core of the new Meirionnydd Nant Conwy constituency, joined by only around 5,000 voters from outside the old county, while about 3,000 voters in that part of Merionethshire which had been placed in Clwyd rather than Gwynedd moved to the new Clwyd South West constituency.

## Members of Parliament
### MPs 1542–1640

| Parliament | Member |
| 1542 | Edward Stanley |
| 1545 | Rhys Vaughan |
| 1547 | Lewis ap Owen |
| 1553 (Mar) | Lewis ap Owen |
| 1553 (Oct) | John Salesbury |
| 1554 (Apr) | Lewis ap Owen |
| 1554 (Nov) | Lewis ap Owen |
| 1555 | |
| 1558 | Ellis Price |
| 1559 (Jan) | John Wyn ap Cadwaladr |
| 1563 (Jan) | Ellis Price |
| 1571 | Hugh Owen |
| 1572 | John Lewis Owen |
| 1584 (Nov) | Cadwaladr Price |
| 1586 | Robert Lloyd |
| 1588 (Nov) | Robert Salusbury |
| 1593 | Griffith Nanney |
| 1597 (Sep) | Thomas Myddelton |
| 1601 (Oct) | Robert Lloyd |
| 1604–1611 | Sir Edward Herbert |
| 1614 | Ellis Lloyd |
| 1621–1622 | William Salisbury |
| 1624 | Henry Wynn |
| 1625 | Henty Wynn |
| 1626 | Edward Vaughan |
| 1628–1629 | Richard Vaughan |
| 1629–1640 | No Parliaments convened |

### MPs 1640–1983

| Year | Year | Member | Party |
| | April 1640 | Henry Wynn | |
| | November 1640 | William Price | Royalist |
| | February 1644 | Price disabled from sitting – seat vacant | Price disabled from sitting – seat vacant |
| | 1646 | Roger Pope | |
| | 1647 | John Jones | |
| | 1653 | Merioneth was not represented in the Barebones Parliament | Merioneth was not represented in the Barebones Parliament |
| | 1654 | John Vaughan | |
| | 1656 | Colonel John Jones | |
| | January 1659 | Lewis Owen | |
| | May 1659 | Merioneth was not represented in the restored Rump | Merioneth was not represented in the restored Rump |
| | April 1660 | Edmund Meyricke | |
| | 1661 | Henry Wynn | |
| | 1673 | William Price | |
| | 1679 | Sir John Wynn | |
| | 1681 | Sir Robert Owen | |
| | 1685 | Sir John Wynn | |
| | 1695 | Hugh Nanney | |
| | 1701 | Richard Vaughan | |
| | 1734 | William Vaughan | Independent |
| | 1768 | John Pugh Pryse | |
| | 1774 | Evan Lloyd Vaughan | Tory |
| | 1792 | Sir Robert Vaughan | Tory |
| | 1836 | Richard Richards | Conservative |
| | 1852 | William Watkin Edward Wynne | Conservative |
| | 1865 | W. R. M. Wynne | Conservative |
| | 1868 | David Williams | Liberal |
| | 1870 | Samuel Holland | Liberal |
| | 1885 | Henry Robertson | Liberal |
| | 1886 | T. E. Ellis | Liberal |
| | 1899 | Owen Morgan Edwards | Liberal |
| | 1900 | Sir Osmond Williams | Liberal |
| | Jan 1910 | Sir Henry Haydn Jones | Liberal |
| | 1945 | Emrys Roberts | Liberal |
| | 1951 | Thomas Jones | Labour |
| | 1966 | Will Edwards | Labour |
| | Feb 1974 | Dafydd Elis-Thomas | Plaid Cymru |
| 1983 | 1983 | constituency abolished: see Meirionnydd Nant Conwy | constituency abolished: see Meirionnydd Nant Conwy |

## Election results
### Elections in the 1830s

General election 1830: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Tory | Robert Vaughan | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 600 | |
| | Tory hold | Tory hold | Tory hold | Tory hold |
General election 1831: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Tory | Robert Vaughan | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 600 | |
| | Tory hold | Tory hold | Tory hold | Tory hold |
General election 1832: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Tory | Robert Vaughan | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 580 | |
| | Tory hold | Tory hold | Tory hold | Tory hold |
General election 1835: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Conservative | Robert Vaughan | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 698 | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold |
Vaughan resigned, causing a by-election.
By-election, 27 June 1836: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Conservative | Richard Richards | 501 | 77.0 |
| | Whig | William Wynn | 150 | 23.0 |
| Majority | Majority | Majority | 351 | 54.0 |
| Turnout | Turnout | Turnout | 651 | 82.9 |
| Registered electors | Registered electors | Registered electors | 785 | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold |
General election 1837: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Conservative | Richard Richards | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 1,336 | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold |

### Elections in the 1840s

General election 1841: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Conservative | Richard Richards | Unopposed | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 1,306 | | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold | Conservative hold |
General election 1847: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Conservative | Richard Richards | Unopposed | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 1,180 | | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold | Conservative hold |

### Elections in the 1850s

General election 1852: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Conservative | William Watkin Edward Wynne | Unopposed | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 1,006 | | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold | Conservative hold |
General election 1857: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Conservative | William Watkin Edward Wynne | Unopposed | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 1,126 | | |
| | Conservative hold | Conservative hold | Conservative hold | Conservative hold | Conservative hold |
General election 1859: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Conservative | William Watkin Edward Wynne | 389 | 52.6 | N/A |
| | Liberal | David Williams | 351 | 47.4 | New |
| Majority | Majority | Majority | 38 | 5.2 | N/A |
| Turnout | Turnout | Turnout | 740 | 67.8 | N/A |
| Registered electors | Registered electors | Registered electors | 1,091 | | |
| | Conservative hold | Conservative hold | Swing | N/A | |

### Elections in the 1860s

General election 1865: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Conservative | W. R. M. Wynne | 610 | 51.3 | −1.3 |
| | Liberal | David Williams | 579 | 48.7 | +1.3 |
| Majority | Majority | Majority | 31 | 2.6 | −2.6 |
| Turnout | Turnout | Turnout | 1,189 | 77.9 | +10.1 |
| Registered electors | Registered electors | Registered electors | 1,527 | | |
| | Conservative hold | Conservative hold | Swing | −1.3 | |
General election 1868: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | David Williams | Unopposed | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 3,185 | | |
| | Liberal gain from Conservative | Liberal gain from Conservative | Liberal gain from Conservative | Liberal gain from Conservative | Liberal gain from Conservative |

### Elections in the 1870s

Williams' death caused a by-election.
By-election, 17 January 1870: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Samuel Holland | 1,610 | 62.6 | N/A |
| | Conservative | Charles John Tottenham | 963 | 37.4 | New |
| Majority | Majority | Majority | 647 | 25.2 | N/A |
| Turnout | Turnout | Turnout | 2,573 | 80.7 | N/A |
| Registered electors | Registered electors | Registered electors | 3,187 | | |
| | Liberal hold | Liberal hold | Swing | N/A | |
General election 1874: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Samuel Holland | Unopposed | Unopposed | Unopposed |
| Registered electors | Registered electors | Registered electors | 3,335 | | |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |

### Elections in the 1880s

General election 1880: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Samuel Holland | 1,860 | 63.4 | N/A |
| | Conservative | Alexander Milne Dunlop | 1,074 | 36.6 | New |
| Majority | Majority | Majority | 786 | 26.8 | N/A |
| Turnout | Turnout | Turnout | 2,934 | 82.2 | N/A |
| Registered electors | Registered electors | Registered electors | 3,571 | | |
| | Liberal hold | Liberal hold | Swing | | |
General election 1885: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Robertson | 3,784 | 47.9 | −15.5 |
| | Conservative | W. R. M. Wynne | 2,209 | 28.0 | −8.6 |
| | Independent Liberal | Morgan Lloyd | 1,907 | 24.1 | New |
| Majority | Majority | Majority | 1,575 | 19.9 | −6.9 |
| Turnout | Turnout | Turnout | 7,900 | 84.6 | +2.4 |
| Registered electors | Registered electors | Registered electors | 9,333 | | |
| | Liberal hold | Liberal hold | Swing | −3.5 | |
General election 1886: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | T. E. Ellis | 4,127 | 59.1 | +11.2 |
| | Conservative | John Vaughan | 2,860 | 40.9 | +12.9 |
| Majority | Majority | Majority | 1,267 | 18.2 | −1.7 |
| Turnout | Turnout | Turnout | 6,987 | 74.9 | −9.7 |
| Registered electors | Registered electors | Registered electors | 9,333 | | |
| | Liberal hold | Liberal hold | Swing | −0.9 | |

### Elections in the 1890s

General election 1892: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | T. E. Ellis | 5,175 | 72.8 | +13.7 |
| | Conservative | Henry Owen | 1,937 | 27.2 | −13.7 |
| Majority | Majority | Majority | 3,238 | 45.6 | +27.4 |
| Turnout | Turnout | Turnout | 7,112 | 77.8 | +2.9 |
| Registered electors | Registered electors | Registered electors | 9,137 | | |
| | Liberal hold | Liberal hold | Swing | +13.7 | |
Ellis was appointed a Lord Commissioner of the Treasury, requiring a by-election.
By-election, 1892: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | T. E. Ellis | Unopposed | Unopposed | Unopposed |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |
General election 1895: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | T. E. Ellis | 5,173 | 69.9 | −2.9 |
| | Conservative | Charles Edward Jones Owen | 2,232 | 30.1 | +2.9 |
| Majority | Majority | Majority | 2,941 | 39.8 | −5.8 |
| Turnout | Turnout | Turnout | 7,405 | 82.4 | +4.6 |
| Registered electors | Registered electors | Registered electors | 8,983 | | |
| | Liberal hold | Liberal hold | Swing | −2.9 | |
Ellis' death caused a by-election.
1899 Merionethshire by-election :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Owen Morgan Edwards | Unopposed | Unopposed | Unopposed |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |

### Elections in the 1900s

General election 1900: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Osmond Williams | Unopposed | Unopposed | Unopposed |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |
General election 1906: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Osmond Williams | Unopposed | Unopposed | Unopposed |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |

### Elections in the 1910s

General election January 1910: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 6,065 | 76.4 | N/A |
| | Conservative | Robert John Morris | 1,873 | 23.6 | New |
| Majority | Majority | Majority | 4,192 | 52.8 | N/A |
| Turnout | Turnout | Turnout | 7,938 | 84.8 | N/A |
| Registered electors | Registered electors | Registered electors | 9,365 | | |
| | Liberal hold | Liberal hold | Swing | N/A | |
General election December 1910: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | Unopposed | Unopposed | Unopposed |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |
General Election 1914–15:
Another General Election was required to take place before the end of 1915. The political parties had been making preparations for an election to take place and by July 1914, the following candidates had been selected;
* Liberal: Henry Haydn Jones
* Unionist: Sam Thompson
General election 1918: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | Unopposed | Unopposed | Unopposed |
| | Liberal hold | Liberal hold | Liberal hold | Liberal hold | Liberal hold |

### Elections in the 1920s

General election 1922: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 9,903 | 58.3 | N/A |
| | Labour | John Jones Roberts | 7,070 | 41.7 | New |
| Majority | Majority | Majority | 2,833 | 16.6 | N/A |
| Turnout | Turnout | Turnout | 16,973 | 77.1 | N/A |
| | Liberal hold | Liberal hold | Swing | N/A | |
General election 1923: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 11,005 | 60.5 | +2.2 |
| | Labour | John Jones Roberts | 7,181 | 39.5 | −2.2 |
| Majority | Majority | Majority | 3,824 | 21.0 | +4.4 |
| Turnout | Turnout | Turnout | 18,186 | 80.2 | +3.1 |
| | Liberal hold | Liberal hold | Swing | +2.2 | |
General election 1924: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 9,228 | 47.8 | −12.7 |
| | Labour | John Jones Roberts | 6,393 | 33.1 | −6.4 |
| | Conservative | Robert Vaughan | 3,677 | 19.1 | New |
| Majority | Majority | Majority | 2,835 | 14.7 | −6.3 |
| Turnout | Turnout | Turnout | 19,298 | 83.9 | +2.7 |
| | Liberal hold | Liberal hold | Swing | | |
General election 1929: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 11,865 | 48.3 | +0.5 |
| | Labour | John Jones Roberts | 7,980 | 32.5 | −0.6 |
| | Conservative | Charles Phibbs | 4,731 | 19.3 | +0.2 |
| Majority | Majority | Majority | 3,885 | 15.8 | +1.1 |
| Turnout | Turnout | Turnout | 24,576 | 85.2 | +1.3 |
| | Liberal hold | Liberal hold | Swing | +0.6 | |

### Elections in the 1930s

General election 1931: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 9,756 | 40.8 | +7.5 |
| | Labour | James Henry Howard | 7,807 | 32.6 | +0.1 |
| | Conservative | Charles Phibbs | 6,372 | 26.6 | +7.3 |
| Majority | Majority | Majority | 1,949 | 8.1 | −7.7 |
| Turnout | Turnout | Turnout | 23,935 | 82.6 | −2.6 |
| | Liberal hold | Liberal hold | Swing | | |
General election 1935: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Henry Haydn Jones | 9,466 | 40.0 | −0.8 |
| | Labour | Thomas Jones | 8,317 | 35.2 | +2.6 |
| | Conservative | Charles Phibbs | 5,868 | 24.8 | −1.8 |
| Majority | Majority | Majority | 1,149 | 4.9 | −3.2 |
| Turnout | Turnout | Turnout | 23,651 | 81.6 | −1.0 |
| | Liberal hold | Liberal hold | Swing | | |
A General election was due to take place before the end of 1940, but was postponed due to the Second World War. By the Autumn of 1939, the following candidates had been selected to contest this constituency;
* Liberal Party: Henry Haydn Jones
* Labour Party: Thomas Jones

### Elections in the 1940s

General election 1945: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Emrys Roberts | 8,495 | 35.8 | −4.2 |
| | Labour | Huw Morris Jones | 8,383 | 35.4 | +0.2 |
| | Conservative | Craig Parry Hughes | 4,374 | 18.5 | −6.3 |
| | Plaid Cymru | Gwynfor Evans | 2,448 | 10.3 | New |
| Majority | Majority | Majority | 112 | 0.4 | −4.5 |
| Turnout | Turnout | Turnout | 23,700 | 82.2 | +0.6 |
| | Liberal hold | Liberal hold | Swing | -2.2 | |

### Elections in the 1950s

General election 1950: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Liberal | Emrys Roberts | 9,647 | 38.8 | +3.0 |
| | Labour | O Parry | 8,577 | 34.5 | −0.9 |
| | Conservative | John Francis Williams-Wynne | 4,374 | 18.5 | 0.0 |
| | Plaid Cymru | Gwynfor Evans | 2,754 | 11.0 | +0.7 |
| Majority | Majority | Majority | 1,070 | 4.3 | +3.9 |
| Turnout | Turnout | Turnout | 25,352 | 88.8 | +6.6 |
| | Liberal hold | Liberal hold | Swing | | |
General election 1951: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Thomas Jones | 10,505 | 43.0 | +8.5 |
| | Liberal | Emrys Roberts | 9,457 | 38.6 | −0.2 |
| | Conservative | Geraint Morgan | 4,505 | 18.4 | −0.1 |
| Majority | Majority | Majority | 1,048 | 4.4 | N/A |
| Turnout | Turnout | Turnout | 24,467 | 87.3 | −1.5 |
| | Labour gain from Liberal | Labour gain from Liberal | Swing | | |
General election 1955: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Thomas Jones | 9,056 | 38.3 | −4.7 |
| | Liberal | Henry Evans Jones | 6,374 | 26.9 | −11.7 |
| | Plaid Cymru | Gwynfor Evans | 5,243 | 22.1 | New |
| | National Liberal | John V Jenkins | 3,001 | 12.7 | −5.7 |
| Majority | Majority | Majority | 2,682 | 11.3 | +6.9 |
| Turnout | Turnout | Turnout | 23,674 | | |
| | Labour hold | Labour hold | Swing | | |
General election 1959: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Thomas Jones | 9,095 | 40.7 | +2.4 |
| | Liberal | Ben Jones | 8,119 | 36.3 | +9.4 |
| | Plaid Cymru | Gwynfor Evans | 5,127 | 23.0 | +0.9 |
| Majority | Majority | Majority | 976 | 4.4 | −6.9 |
| Turnout | Turnout | Turnout | 22,341 | | |
| | Labour hold | Labour hold | Swing | | |

### Elections in the 1960s

General election 1964: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Thomas Jones | 8,420 | 38.37 | |
| | Liberal | Richard O Jones | 7,171 | 32.68 | |
| | Plaid Cymru | Elystan Morgan | 3,697 | 16.85 | |
| | Conservative | A E Campbell L Jones-Lloyd | 2,656 | 12.10 | New |
| Majority | Majority | Majority | 1,249 | 5.69 | |
| Turnout | Turnout | Turnout | 21,944 | 83.15 | |
| | Labour hold | Labour hold | Swing | | |
General election 1966: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Labour | William Edwards | 9,628 | 44.17 |
| | Liberal | Edward Gwyn Jones | 7,733 | 35.47 |
| | Plaid Cymru | Ieuan Lewis Jenkins | 2,490 | 11.42 |
| | Conservative | A E Campbell L Jones-Lloyd | 1,948 | 8.94 |
| Majority | Majority | Majority | 1,895 | 8.70 |
| Turnout | Turnout | Turnout | 21,799 | 85.84 |
| | Labour hold | Labour hold | Swing | |

### Elections in the 1970s

General election 1970: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Labour | William Edwards | 8,861 | 39.76 |
| | Plaid Cymru | Dafydd Wigley | 5,425 | 24.34 |
| | Liberal | Emlyn Thomas | 5,034 | 22.59 |
| | Conservative | D Elgan H Edwards | 2,965 | 13.30 |
| Majority | Majority | Majority | 3,436 | 15.42 |
| Turnout | Turnout | Turnout | 22,285 | 84.24 |
| | Labour hold | Labour hold | Swing | |
General election February 1974: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Plaid Cymru | Dafydd Elis-Thomas | 7,823 | 34.61 | |
| | Labour | William Edwards | 7,235 | 32.01 | |
| | Liberal | IAE Jones | 4,153 | 18.37 | |
| | Conservative | RR Owen | 3,392 | 15.01 | |
| Majority | Majority | Majority | 588 | 2.60 | N/A |
| Turnout | Turnout | Turnout | 22,603 | 85.26 | |
| | Plaid Cymru gain from Labour | Plaid Cymru gain from Labour | Swing | | |
General election October 1974: Merioneth :
| Party | Party | Candidate | Votes | % |
| | Plaid Cymru | Dafydd Elis-Thomas | 9,543 | 42.49 |
| | Labour | William Edwards | 6,951 | 30.95 |
| | Liberal | Richard O Jones | 3,454 | 15.38 |
| | Conservative | RR Owen | 2,509 | 11.17 |
| Majority | Majority | Majority | 2,592 | 11.54 |
| Turnout | Turnout | Turnout | 22,457 | 84.02 |
| | Plaid Cymru hold | Plaid Cymru hold | Swing | |
General election 1979: Merioneth :
| Party | Party | Candidate | Votes | % | ±% |
| | Plaid Cymru | Dafydd Elis-Thomas | 9,275 | 40.8 | −1.7 |
| | Conservative | Robert Harvey | 5,365 | 23.6 | +12.4 |
| | Labour | RH Jones | 5,332 | 23.5 | −7.4 |
| | Liberal | John Parsons | 2,752 | 12.1 | −3.3 |
| Majority | Majority | Majority | 3,910 | 17.2 | +5.7 |
| Turnout | Turnout | Turnout | 22,724 | 83.4 | −0.6 |
| | Plaid Cymru hold | Plaid Cymru hold | Swing | | |