# Cynon Valley (UK Parliament constituency)

Cynon Valley (Welsh: Cwm Cynon) was a constituency in Wales, of the House of Commons of the UK Parliament from 1983 to 2024. Its last MP from 2019 to 2024 was Beth Winter of the Labour Party.
The Cynon Valley Senedd constituency was created with the same boundaries in 1999 (as an Assembly constituency).
The constituency was abolished as part of the 2023 periodic review of Westminster constituencies and under the June 2023 final recommendations of the Boundary Commission for Wales. Its wards were split between Merthyr Tydfil and Aberdare, and Pontypridd.

## Boundaries

1983–2010: The Borough of Cynon Valley.
2010–2024: The Rhondda Cynon Taff County Borough electoral divisions of Aberaman North, Aberaman South, Abercynon, Aberdare East, Aberdare West/Llwydcoed, Cilfynydd, Cwmbach, Glyncoch, Hirwaun, Mountain Ash East, Mountain Ash West, Penrhiwceiber, Pen-y-waun, Rhigos, and Ynysybwl.
The constituency encompasses the towns of Aberdare, Mountain Ash, Cilfynydd, Abercynon and Hirwaun.

## Members of Parliament

| Election | Member | Party |
| 1983 | Ioan Evans | Labour Co-op |
| 1984 by-election | Ann Clwyd | Labour |
| 2019 | Beth Winter | Labour |
| 2024 | Constituency abolished | Constituency abolished |

## Elections
### Elections in the 1980s

General election 1983: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour Co-op | Ioan Evans | 20,668 | 56.0 | N/A |
| | SDP | Felix Aubel | 7,594 | 20.6 | N/A |
| | Conservative | James Arbuthnot | 5,240 | 14.2 | N/A |
| | Plaid Cymru | Pauline Jarman | 3,421 | 9.3 | N/A |
| Majority | Majority | Majority | 13,074 | 35.4 | N/A |
| Turnout | Turnout | Turnout | 36,923 | 73.4 | N/A |
| Registered electors | Registered electors | Registered electors | 50,284 | | |
| | Labour Co-op win (new seat) | Labour Co-op win (new seat) | Labour Co-op win (new seat) | Labour Co-op win (new seat) | Labour Co-op win (new seat) |
1984 Cynon Valley by-election :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 19,389 | 58.8 | +2.8 |
| | SDP | Felix Aubel | 6,554 | 19.9 | −0.7 |
| | Plaid Cymru | Clayton F. Jones | 3,619 | 11.0 | +1.8 |
| | Conservative | James Arbuthnot | 2,441 | 7.4 | −6.8 |
| | Communist | Mary Winter | 642 | 1.9 | N/A |
| | Independent | Noel E. Rencontre | 215 | 0.6 | N/A |
| | Independent | Paul Nicholls-Jones | 122 | 0.4 | N/A |
| Majority | Majority | Majority | 12,835 | 38.9 | +3.5 |
| Turnout | Turnout | Turnout | 32,982 | 65.7 | −7.7 |
| Registered electors | Registered electors | Registered electors | 50,237 | | |
| | Labour hold | Labour hold | Swing | | |
General election 1987: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 26,222 | 68.9 | +12.9 |
| | SDP | Keith Butler | 4,651 | 12.2 | −8.4 |
| | Conservative | Mark Bishop | 4,638 | 12.2 | −2.0 |
| | Plaid Cymru | Dorothy Richards | 2,549 | 6.7 | −2.6 |
| Majority | Majority | Majority | 21,571 | 56.7 | +21.3 |
| Turnout | Turnout | Turnout | 38,060 | 76.7 | +3.3 |
| Registered electors | Registered electors | Registered electors | 49,621 | | |
| | Labour hold | Labour hold | Swing | | |

### Elections in the 1990s

General election 1992: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 26,254 | 69.1 | +0.2 |
| | Conservative | Andrew Smith | 4,890 | 12.9 | +0.7 |
| | Plaid Cymru | Clifford Benney | 4,186 | 11.0 | +4.3 |
| | Liberal Democrats | Marcello Verma | 2,667 | 7.0 | −5.2 |
| Majority | Majority | Majority | 21,364 | 56.2 | −0.5 |
| Turnout | Turnout | Turnout | 37,997 | 76.5 | −0.2 |
| Registered electors | Registered electors | Registered electors | 49,695 | | |
| | Labour hold | Labour hold | Swing | −0.2 | |
General election 1997: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 23,307 | 69.7 | +0.6 |
| | Plaid Cymru | Alun Davies | 3,552 | 10.6 | −0.4 |
| | Liberal Democrats | Huw Price | 3,459 | 10.3 | +3.3 |
| | Conservative | Andrew Smith | 2,260 | 6.8 | −6.1 |
| | Referendum | Gwyn John | 844 | 2.5 | N/A |
| Majority | Majority | Majority | 19,755 | 59.1 | +2.9 |
| Turnout | Turnout | Turnout | 33,422 | 69.2 | −7.3 |
| Registered electors | Registered electors | Registered electors | 48,286 | | |
| | Labour hold | Labour hold | Swing | +0.5 | |

### Elections in the 2000s

General election 2001: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 17,685 | 65.6 | −4.1 |
| | Plaid Cymru | Steven J. Cornelius | 4,687 | 17.4 | +6.8 |
| | Liberal Democrats | Ian Parry | 2,541 | 9.4 | −0.9 |
| | Conservative | Julian Waters | 2,045 | 7.6 | +0.8 |
| Majority | Majority | Majority | 12,998 | 48.2 | −10.9 |
| Turnout | Turnout | Turnout | 26,958 | 55.4 | −13.8 |
| Registered electors | Registered electors | Registered electors | 48,639 | | |
| | Labour hold | Labour hold | Swing | −5.4 | |
General election 2005: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 17,074 | 64.1 | −1.5 |
| | Plaid Cymru | Geraint Benney | 3,815 | 14.3 | −3.1 |
| | Liberal Democrats | Margaret Phelps | 2,991 | 11.2 | +1.8 |
| | Conservative | Antonia Dunn | 2,062 | 7.7 | +0.1 |
| | UKIP | Sue Davies | 705 | 2.6 | N/A |
| Majority | Majority | Majority | 13,259 | 49.8 | +1.6 |
| Turnout | Turnout | Turnout | 26,647 | 58.7 | +3.3 |
| Registered electors | Registered electors | Registered electors | 44,803 | | |
| | Labour hold | Labour hold | Swing | +0.8 | |

### Elections in the 2010s

General election 2010: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 15,681 | 52.5 | −10.5 |
| | Plaid Cymru | Dafydd Trystan Davies | 6,064 | 20.3 | +6.8 |
| | Liberal Democrats | Lee Thacker | 4,120 | 13.8 | +1.6 |
| | Conservative | Juliette Ash | 3,010 | 10.1 | +2.1 |
| | UKIP | Frank Hughes | 1,001 | 3.4 | +0.7 |
| Majority | Majority | Majority | 9,617 | 32.2 | −17.6 |
| Turnout | Turnout | Turnout | 29,876 | 59.0 | −1.3 |
| Registered electors | Registered electors | Registered electors | 50,650 | | |
| | Labour hold | Labour hold | Swing | −8.6 | |
General election 2015: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 14,532 | 47.7 | −4.8 |
| | Plaid Cymru | Cerith Griffiths | 5,126 | 16.8 | −3.5 |
| | UKIP | Rebecca Rees-Evans | 4,976 | 16.3 | +12.9 |
| | Conservative | Keith Dewhurst | 3,676 | 12.1 | +2.0 |
| | Liberal Democrats | Angharad Jones | 830 | 2.7 | −11.1 |
| | Green | John Matthews | 799 | 2.6 | N/A |
| | Socialist Labour | Chris Beggs | 533 | 1.7 | N/A |
| Rejected ballots | Rejected ballots | Rejected ballots | 81 | | |
| Majority | Majority | Majority | 9,406 | 30.9 | −1.3 |
| Turnout | Turnout | Turnout | 30,472 | 59.3 | +0.3 |
| Registered electors | Registered electors | Registered electors | 51,422 | | |
| | Labour hold | Labour hold | Swing | −0.6 | |
Of the 81 rejected ballots:
* 59 were either unmarked or it was uncertain who the vote was for.
* 22 voted for more than one candidate.
General election 2017: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Ann Clwyd | 19,404 | 61.0 | +13.3 |
| | Conservative | Keith Dewhurst | 6,166 | 19.4 | +7.3 |
| | Plaid Cymru | Liz Walters | 4,376 | 13.8 | −3.0 |
| | UKIP | Ian McLean | 1,271 | 4.0 | −12.3 |
| | Liberal Democrats | Nicola Knight | 585 | 1.8 | −0.9 |
| Majority | Majority | Majority | 13,238 | 41.6 | +11.7 |
| Turnout | Turnout | Turnout | 31,802 | 62.0 | +2.7 |
| Registered electors | Registered electors | Registered electors | 51,334 | | |
| | Labour hold | Labour hold | Swing | +3.0 | |
General election 2019: Cynon Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Labour | Beth Winter | 15,533 | 51.4 | −9.6 |
| | Conservative | Pauline Church | 6,711 | 22.2 | +2.8 |
| | Brexit Party | Rebecca Rees-Evans | 3,045 | 10.1 | N/A |
| | Plaid Cymru | Geraint Benney | 2,562 | 8.5 | −5.3 |
| | Cynon Valley | Andrew Chainey | 1,322 | 4.4 | N/A |
| | Liberal Democrats | Steve Bray | 949 | 3.1 | +1.3 |
| | SDP | Ian McLean | 114 | 0.4 | N/A |
| Majority | Majority | Majority | 8,822 | 29.2 | −12.4 |
| Turnout | Turnout | Turnout | 30,236 | 59.1 | −2.9 |
| Registered electors | Registered electors | Registered electors | 51,134 | | |
| | Labour hold | Labour hold | Swing | -6.2 | |