# Merthyr (UK Parliament constituency)

Merthyr was a borough constituency centred on the town of Merthyr Tydfil in Wales. It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom.
The constituency was created for the 1918 general election, and abolished for the 1950 general election, when it was largely replaced by the new constituency of Merthyr Tydfil.

## Members of Parliament

| Election | Election | Member | Party |
| | 1918 | Sir Edgar Rees Jones | Coalition Liberal |
| | 1922 | R. C. Wallhead | Labour |
| | 1931 | R. C. Wallhead | ILP |
| | 1933 | R. C. Wallhead | Labour |
| | 1934 by-election | S. O. Davies | Labour |
| 1950 | 1950 | constituency abolished: see Merthyr Tydfil | constituency abolished: see Merthyr Tydfil |

## Election results
### Elections in the 1910s

General election 1918: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| C | Liberal | Edgar Rees Jones | 14,127 | 52.7 | |
| | Labour | James Winstone | 12,682 | 47.3 | |
| Majority | Majority | Majority | 1,445 | 5.4 | ' |
| Turnout | Turnout | Turnout | 26,809 | 76.5 | |
| Registered electors | Registered electors | Registered electors | 35,049 | | |
| | Liberal win (new seat) | Liberal win (new seat) | Liberal win (new seat) | Liberal win (new seat) | Liberal win (new seat) |
| C indicates candidate endorsed by the coalition government. ||||||

### Elections in the 1920s

General election 1922: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | R. C. Wallhead | 17,516 | 53.0 | +5.7 |
| | Independent and Anti-Socialist | Richard Mathias | 15,552 | 47.0 | New |
| Majority | Majority | Majority | 1,964 | 6.0 | N/A |
| Turnout | Turnout | Turnout | 33,068 | 90.6 | +14.1 |
| Registered electors | Registered electors | Registered electors | 36,514 | | |
| | Labour gain from Liberal | Labour gain from Liberal | Swing | N/A | |
General election 1923: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | R. C. Wallhead | 19,511 | 60.1 | +7.1 |
| | Liberal | David Rowland Thomas | 7,403 | 22.8 | New |
| | Unionist | Arthur Fox-Davies | 5,548 | 17.1 | New |
| Majority | Majority | Majority | 12,108 | 37.3 | +31.3 |
| Turnout | Turnout | Turnout | 32,462 | 86.8 | −3.8 |
| Registered electors | Registered electors | Registered electors | 37,413 | | |
| | Labour hold | Labour hold | Swing | N/A | |
General election 1924: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | R. C. Wallhead | 19,882 | 59.8 | −0.3 |
| | Unionist | Arthur Fox-Davies | 13,383 | 40.2 | +23.1 |
| Majority | Majority | Majority | 6,499 | 19.6 | −17.7 |
| Turnout | Turnout | Turnout | 33,265 | 86.9 | +0.1 |
| Registered electors | Registered electors | Registered electors | 38,276 | | |
| | Labour hold | Labour hold | Swing | -11.7 | |
General election 1929: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | R. C. Wallhead | 22,701 | 59.6 | −0.2 |
| | Liberal | James Jenkins | 8,696 | 22.8 | New |
| | Unionist | Francis Bradley-Birt | 6,712 | 17.6 | −22.6 |
| Majority | Majority | Majority | 14,005 | 36.8 | +17.2 |
| Turnout | Turnout | Turnout | 38,109 | 85.8 | −1.1 |
| Registered electors | Registered electors | Registered electors | 44,408 | | |
| | Labour hold | Labour hold | Swing | | |

### Elections in the 1930s

General election 1931: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Ind. Labour Party | R. C. Wallhead | 24,623 | 69.4 | +9.8 |
| | New Party | Sellick Davies | 10,834 | 30.6 | New |
| Majority | Majority | Majority | 13,789 | 38.8 | N/A |
| Turnout | Turnout | Turnout | 35,547 | 80.8 | −5.0 |
| Registered electors | Registered electors | Registered electors | 43,908 | | |
| | Ind. Labour Party gain from Labour | Ind. Labour Party gain from Labour | Swing | N/A | |
1934 Merthyr by-election :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | S. O. Davies | 18,645 | 51.8 | New |
| | Liberal | Victor Evans | 10,376 | 28.9 | New |
| | Ind. Labour Party | Campbell Stephen | 3,508 | 9.8 | −59.6 |
| | Communist | Wal Hannington | 3,409 | 9.5 | New |
| Majority | Majority | Majority | 8,269 | 22.9 | N/A |
| Turnout | Turnout | Turnout | 35,938 | 81.1 | +0.3 |
| Registered electors | Registered electors | Registered electors | 44,286 | | |
| | Labour gain from Ind. Labour Party | Labour gain from Ind. Labour Party | Swing | | |
General election 1935: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | S. O. Davies | 20,530 | 68.0 | N/A |
| | Ind. Labour Party | Claude Stanfield | 9,640 | 32.0 | −37.4 |
| Majority | Majority | Majority | 10,890 | 36.0 | N/A |
| Turnout | Turnout | Turnout | 30,170 | 68.8 | −12.0 |
| Registered electors | Registered electors | Registered electors | 43,842 | | |
| | Labour gain from Ind. Labour Party | Labour gain from Ind. Labour Party | Swing | N/A | |

### Elections in the 1940s

General election 1945: Merthyr :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | S. O. Davies | 24,879 | 81.4 | +13.4 |
| | Independent Labour | Samuel Jennings | 5,693 | 18.6 | New |
| Majority | Majority | Majority | 19,186 | 62.8 | +36.8 |
| Turnout | Turnout | Turnout | 30,572 | 68.6 | −0.2 |
| Registered electors | Registered electors | Registered electors | 44,540 | | |
| | Labour hold | Labour hold | Swing | N/A | |