New Boundaries: Northern Ireland (UK) Parliamentary forecast by Electoral Calculus

New parliamentary boundaries were announced on 6 September by the Boundary Commission for Northern Ireland. Analysis of these initial proposals by Electoral Calculus indicates the the Ulster Unionist Party may lose both of its current Westminster seats, and that the republican Sinn Féin is likely to gain two seats, if voting patterns remain stable. The centre-left nationalist SDLP are also expected to lose one seat, as the total number of seats in the province decreases from 18 to 17.

The projected loss of the Ulster Unionist's MPs would be a heavy blow for the century-old party which has historically dominated Northern Ireland politics. Its influential past leaders include James Molyneux and David Trimble, who was the first-ever First Minister of Northern Ireland (1998-2002). Recently it has been eclipsed by the Democratic Unionist Party, founded by Ian Paisley in the 1970s, which is now the largest NI party at Westminster.

The UUP's two current seats are Antrim South, and Fermanagh and South Tyrone. The former is split and mostly becomes the new seat of 'Antrim West' which is predicted to be DUP. The latter seat, whose current UUP majority is only 530 votes, gains nationalist voters from Tyrone West, and is slated to become Sinn Féin's.

Other changes include the dismemberment into fragments of Belfast South (SDLP), and Ulster Mid (SF), which effectively disappear as seats. But Sinn Féin more than compensates for this by taking Upper Bann, and Londonderry East (renamed 'Glenshane') from the DUP. There is also one new seat created called Down West, which is predicted to be won by the DUP.

PartyOld SeatsNew SeatsChangeCommentary
DUP880Lose Londonderry East and Upper Bann;
gain Antrim West, and Down West (new seat)
SF46+2Gain Upper Bann and BlackwaterGlenshane,
Fermanagh and South Tyrone; lose Ulster Mid (disappears)
SDLP32-1Lose Belfast South (disappearing seat)
UUP20-2Lose Antrim South, Fermanagh and South Tyrone
MIN110Hold Down North
See Northern Ireland boundary changes for full details of every old and new seat in NI.
See New Boundaries 2018 overall analysis.