# Lagan Valley (UK Parliament constituency)

Lagan Valley is a parliamentary constituency in the United Kingdom House of Commons.
The constituency always returned unionist MPs from its creation until the 2024 general election, when it elected Sorcha Eastwood of the Alliance Party.

## History

For the history of the equivalent constituencies prior to 1950, see Antrim (UK Parliament constituency) and Down (UK Parliament constituency) and from 1950 until 1983, please see South Antrim (UK Parliament constituency) and North Down.

## Boundaries

1983–1997: The District of Lisburn, and the Borough of Castlereagh ward of Carryduff.
1997–2010: The District of Lisburn wards of Ballinderry, Ballymacash, Ballymacbrennan, Ballymacoss, Blaris, Derryaghy, Dromara, Drumbo, Dunmurry, Glenavy, Harmony Hill, Hilden, Hillhall, Hillsborough, Knockmore, Lagan Valley, Lambeg, Lisnagarvey, Maghaberry, Magheralave, Maze, Moira, Old Warren, Seymour Hill, Tonagh, and Wallace Park, and the District of Banbridge wards of Dromore North, Dromore South, Gransha, and Quilly.
2010–2024: The City of Lisburn wards of Ballinderry, Ballymacash, Ballymacbrennan, Ballymacoss, Blaris, Dromara, Drumbo, Harmony Hill, Hilden, Hillhall, Hillsborough, Knockmore, Lagan Valley, Lambeg, Lisnagarvey, Maghaberry, Magheralave, Maze, Moira, Old Warren, Seymour Hill, Tonagh, Wallace Park, and part of Derryaghy; the District of Banbridge wards of Dromore North, Dromore South, Gransha, and Quilly and the Ballynahatty and Edenderry parts of the Belvoir ward of the City of Belfast.
2024–present: The District of Armagh, Banbridge and Craigavon wards of Aghagallon, Donaghcloney, Dromore, Gransha, Magheralin, and Quilly; and the District of Lisburn and Castlereagh wards of Ballinderry, Ballymacash, Ballymacbrennan, Ballymacoss, Blaris, Dromara, Harmony Hill, Hilden, Hillhall, Hillsborough, Knockmore, Lagan, Lagan Valley, Lambeg, Lisnagarvey, Maghaberry, Magheralave, Maze, Moira, Old Warren, Ravernet, Wallace Park, and White Mountain.
The seat was created in 1983, as part of an expansion of Northern Ireland's constituencies from 12 to 17, and was predominantly made up from parts of South Antrim and North Down. In their original proposals, in January 1980, the boundary commission proposed calling it 'Lagan'. In further revisions in 1995 it lost some areas to both Belfast West and Strangford.
Following their review of all parliamentary seats in Northern Ireland prior to the 2010 United Kingdom general election the Boundary Commission for Northern Ireland made alterations to Lagan Valley. In an unprecedented decision, passed by Parliament through the Northern Ireland Parliamentary Constituencies Order, one electoral ward was split between two constituencies. This followed concerns in Derriaghy about being moved into the neighbouring but republican West Belfast seat.

## Members of Parliament

The Member of Parliament since 1997 was Sir Jeffrey Donaldson who was elected as a member of the Ulster Unionist Party but switched to the Democratic Unionist Party in 2004. He succeeded James Molyneaux who had represented the seat for the UUP since the 1983 general election and previously sat for the old South Antrim constituency which covered much of the same area. Donaldson was elected Leader of the DUP in June 2021, but resigned the leadership in March 2024.
| Election | Member | Party |
| 1983 | Sir James Molyneaux | Ulster Unionist |
| 1997 | Sir Jeffrey Donaldson | Ulster Unionist |
| 2004 | Sir Jeffrey Donaldson | Democratic Unionist |
| 2024 | Sir Jeffrey Donaldson | Independent Unionist |
| 2024 | Sorcha Eastwood | Alliance |

## Elections
### Elections in the 2020s

General election 2024: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | Alliance | Sorcha Eastwood | 18,618 | 37.9 | +10.8 |
| | DUP | Jonathan Buckley | 15,659 | 31.9 | −11.5 |
| | UUP | Robbie Butler | 11,157 | 22.7 | +4.2 |
| | TUV | Lorna Smyth | 2,186 | 4.5 | New |
| | SDLP | Simon Lee | 1,028 | 2.1 | −2.0 |
| | Green (NI) | Patricia Denvir | 433 | 0.9 | New |
| Majority | Majority | Majority | 2,959 | 6.0 | N/A |
| Turnout | Turnout | Turnout | 49,081 | 60.0 | −0.2 |
| Registered electors | Registered electors | Registered electors | 82,201 | | |
| | Alliance gain from DUP | Alliance gain from DUP | Swing | +11.15 | |

### Elections in the 2010s

General election 2019: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | DUP | Jeffrey Donaldson | 19,586 | 43.1 | −16.5 |
| | Alliance | Sorcha Eastwood | 13,087 | 28.8 | +17.7 |
| | UUP | Robbie Butler | 8,606 | 19.0 | +2.2 |
| | SDLP | Ally Haydock | 1,758 | 3.9 | −3.6 |
| | Sinn Féin | Gary McCleave | 1,098 | 2.4 | −1.1 |
| | NI Conservatives | Gary Hynds | 955 | 2.1 | +1.1 |
| | UKIP | Alan Love | 315 | 0.7 | New |
| Majority | Majority | Majority | 6,499 | 14.3 | −28.5 |
| Turnout | Turnout | Turnout | 45,405 | 60.0 | −2.2 |
| Registered electors | Registered electors | Registered electors | 75,675 | | |
| | DUP hold | DUP hold | Swing | −17.1 | |
This seat saw a swing towards the Alliance Party of over 17%, and the largest decrease in vote share for the DUP at the 2019 general election.
General election 2017: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | DUP | Jeffrey Donaldson | 26,762 | 59.6 | +11.7 |
| | UUP | Robbie Butler | 7,533 | 16.8 | +1.6 |
| | Alliance | Aaron McIntyre | 4,996 | 11.1 | −2.8 |
| | SDLP | Pat Catney | 3,384 | 7.5 | +1.2 |
| | Sinn Féin | Jacqui Russell | 1,567 | 3.5 | +0.6 |
| | NI Conservatives | Ian Nickels | 462 | 1.0 | −0.6 |
| | Independent | Jonny Orr | 222 | 0.5 | −1.4 |
| Majority | Majority | Majority | 19,229 | 42.8 | +10.1 |
| Turnout | Turnout | Turnout | 45,044 | 62.2 | +6.3 |
| Registered electors | Registered electors | Registered electors | 72,380 | | |
| | DUP hold | DUP hold | Swing | +5.1 | |
General election 2015: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | DUP | Jeffrey Donaldson | 19,055 | 47.9 | −1.9 |
| | UUP | Alexander Redpath | 6,055 | 15.2 | −5.9 |
| | Alliance | Trevor Lunn | 5,544 | 13.9 | +2.5 |
| | SDLP | Pat Catney | 2,500 | 6.3 | +1.3 |
| | UKIP | Alan Love | 2,200 | 5.5 | New |
| | TUV | Samuel Morrison | 1,887 | 4.7 | −3.9 |
| | Sinn Féin | Jacqui McGeough | 1,144 | 2.9 | −1.1 |
| | Independent | Jonny Orr | 756 | 1.9 | New |
| | NI Conservatives | Helen Osborne | 654 | 1.6 | New |
| Majority | Majority | Majority | 13,000 | 32.7 | +4.0 |
| Turnout | Turnout | Turnout | 39,795 | 55.9 | −0.1 |
| Registered electors | Registered electors | Registered electors | 71,152 | | |
| | DUP hold | DUP hold | Swing | +2.0 | |
General election 2010: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | DUP | Jeffrey Donaldson | 18,199 | 49.8 | −8.5 |
| | UCU-NF | Daphne Trimble | 7,713 | 21.1 | −1.8 |
| | Alliance | Trevor Lunn | 4,174 | 11.4 | +0.5 |
| | TUV | Keith Harbinson | 3,154 | 8.6 | +8.6 |
| | SDLP | Brian Heading | 1,835 | 5.0 | −1.1 |
| | Sinn Féin | Paul Butler | 1,465 | 4.0 | −3.5 |
| Majority | Majority | Majority | 10,486 | 28.7 | −4.5 |
| Turnout | Turnout | Turnout | 36,540 | 56.0 | −4.2 |
| Registered electors | Registered electors | Registered electors | 65,257 | | |
| | DUP hold | DUP hold | Swing | −3.4 | |

### Elections in the 2000s

General election 2005: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | DUP | Jeffrey Donaldson | 23,289 | 54.7 | +41.3 |
| | UUP | Basil McCrea | 9,172 | 21.5 | −35.0 |
| | Alliance | Seamus Close | 4,316 | 10.1 | −6.5 |
| | Sinn Féin | Paul Butler | 3,197 | 7.5 | +1.6 |
| | SDLP | Patricia Lewsley | 2,598 | 6.1 | −1.4 |
| Majority | Majority | Majority | 14,117 | 33.2 | N/A |
| Turnout | Turnout | Turnout | 42,572 | 60.2 | −3.0 |
| Registered electors | Registered electors | Registered electors | 70,238 | | |
| | DUP gain from UUP | DUP gain from UUP | Swing | +38.1 | |
General election 2001: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | UUP | Jeffrey Donaldson | 25,966 | 56.5 | +1.1 |
| | Alliance | Seamus Close | 7,624 | 16.6 | −0.6 |
| | DUP | Edwin Poots | 6,164 | 13.4 | −0.2 |
| | SDLP | Patricia Lewsley | 3,462 | 7.5 | −0.3 |
| | Sinn Féin | Paul Butler | 2,725 | 5.9 | +3.4 |
| Majority | Majority | Majority | 18,342 | 39.9 | −1.7 |
| Turnout | Turnout | Turnout | 45,941 | 63.2 | +1.1 |
| Registered electors | Registered electors | Registered electors | 72,671 | | |
| | UUP hold | UUP hold | Swing | +0.9 | |

### Elections in the 1990s

General election 1997: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | UUP | Jeffrey Donaldson | 24,560 | 55.4 | −5.4 |
| | Alliance | Seamus Close | 7,635 | 17.2 | +4.5 |
| | DUP | Edwin Poots | 6,005 | 13.6 | New |
| | SDLP | Dolores Kelly | 3,436 | 7.8 | −1.7 |
| | NI Conservatives | Stuart E. Sexton | 1,212 | 2.7 | −6.3 |
| | Sinn Féin | Sue Ramsey | 1,110 | 2.5 | +0.4 |
| | Workers' Party | Frances McCarthy | 203 | 0.5 | −0.7 |
| | Natural Law | Hugh Finlay | 149 | 0.3 | New |
| Majority | Majority | Majority | 16,925 | 38.2 | −9.9 |
| Turnout | Turnout | Turnout | 44,310 | 62.1 | −5.2 |
| Registered electors | Registered electors | Registered electors | 71,341 | | |
| | UUP hold | UUP hold | Swing | −8.5 | |
General election 1992: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | UUP | James Molyneaux | 29,772 | 60.8 | −9.2 |
| | Alliance | Seamus Close | 6,207 | 12.7 | −1.1 |
| | SDLP | Hugh Lewsley | 4,626 | 9.5 | +2.6 |
| | NI Conservatives | Timothy R. Coleridge | 4,423 | 9.0 | New |
| | Sinn Féin | Patrick Joseph Rice | 3,346 | 6.8 | +0.4 |
| | Workers' Party | Ann Marie Lowry | 582 | 1.2 | −1.7 |
| Majority | Majority | Majority | 23,565 | 48.1 | −8.1 |
| Turnout | Turnout | Turnout | 48,956 | 67.3 | +2.9 |
| Registered electors | Registered electors | Registered electors | 72,645 | | |
| | UUP hold | UUP hold | Swing | | |

### Elections in the 1980s

General election 1987: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | UUP | James Molyneaux | 29,101 | 70.0 | +10.8 |
| | Alliance | Seamus Close | 5,728 | 13.8 | +2.5 |
| | SDLP | Billy McDonnell | 2,888 | 6.9 | +0.5 |
| | Sinn Féin | Patrick Joseph Rice | 2,656 | 6.4 | +2.1 |
| | Workers' Party | John Lowry | 1,215 | 2.9 | +0.9 |
| Majority | Majority | Majority | 23,373 | 56.2 | +13.8 |
| Turnout | Turnout | Turnout | 41,588 | 64.4 | −3.2 |
| Registered electors | Registered electors | Registered electors | 64,873 | | |
| | UUP hold | UUP hold | Swing | | |
1986 Lagan Valley by-election :
| Party | Party | Candidate | Votes | % | ±% |
| | UUP | James Molyneaux | 32,514 | 90.7 | +31.5 |
| | Workers' Party | John Lowry | 3,328 | 9.3 | +7.3 |
| Majority | Majority | Majority | 29,186 | 81.4 | +39.0 |
| Turnout | Turnout | Turnout | 35,842 | 57.8 | −9.8 |
| Registered electors | Registered electors | Registered electors | 63,244 | | |
| | UUP hold | UUP hold | Swing | | |
General election 1983: Lagan Valley :
| Party | Party | Candidate | Votes | % | ±% |
| | UUP | James Molyneaux | 24,017 | 59.2 | |
| | DUP | William John Beattie | 6,801 | 16.8 | |
| | Alliance | Seamus Close | 4,593 | 11.3 | |
| | SDLP | Cormac Joseph Boomer | 2,603 | 6.4 | |
| | Sinn Féin | Richard McAuley | 1,751 | 4.3 | |
| | Workers' Party | Gerard Loughlin | 809 | 2.0 | |
| Majority | Majority | Majority | 17,216 | 42.4 | |
| Turnout | Turnout | Turnout | 40,574 | 67.6 | |
| Registered electors | Registered electors | Registered electors | 60,051 | | |
| | UUP win (new seat) | UUP win (new seat) | UUP win (new seat) | UUP win (new seat) | UUP win (new seat) |