The Lagan Valley constituency is made up of the Lisburn council area, as it was prior to the amalgamation with Castlereagh, and the Dromore area of the Banbridge council.
It is traditionally a safe unionist seat with the DUP’s Jeffrey Donaldson being returned to Westminster in 2010 with majority of more than 10,000.
At the last general election, the DUP’s main threat came from Ulster Unionist Daphne Trimble who stood as a joint UUP/Conservative candidate (UCUNF).
However, the collaboration failed to enthuse the unionist electorate and the wife of the former first minister, David Trimble, polled just 7,713 votes compared to the sitting MP’s 18,199.
Mr Donaldson originally held the seat as an Ulster Unionist, having succeeded the former UUP leader James Molyneaux as MP in 1997. He was re-elected in 2001 before defecting to the DUP and retaining his seat in 2005.
He will again defend his seat on May 7 with the UUP fielding young solicitor and Lisburn councillor Alex Redpath as its candidate.
The constituency remained unchanged when the boundaries were last re-drawn.
Prior to that, in 2010, Lagan Valley lost the Glenavy ward to South Antrim and Dunmurry to West Belfast.
The two main unionist parties were joined on the 2010 ballot paper by Trevor Lunn, the Alliance MLA, who polled 4,174 votes, Keith Harbinson of the TUV with 3,154, Brian Heading of the SDLP who took 1,835 and Paul Butler of Sinn Fein who polled 1,465 votes. The turnout was 56.2 per cent.
All six parties are represented again — along with candidates from Ukip (Alan Love), Conservatives (Helen Osborne) and an independent (Jonny Orr).
The TUV candidate this time is Jim Allister’s personal assistant and press officer, Sammy Morrison, who lives in Dromore.
Mr Donaldson said there was no question of complacency, despite the constituency being seen as one of the DUP’s safest seats.
“People are very interested in the hung parliament scenario, and a lot of people have said they are voting for the DUP because they want to have a strong Northern Ireland voice at Westminster.
“Immigration has been mentioned by a number of people, Europe, defence has been mentioned — those are the sort of national issues we are picking up on. On a local level we have had everything from John Lewis coming to Sprucefield, to local education issues and the number of schools in Lisburn.”
Political commentator and former Alliance deputy leader Seamus Close believes that the almost certainty that the sitting MP will be returned leads to some lesser known names appearing on the ballot paper.
“In the likes of Lagan Valley where the result is pretty much a foregone conclusion, people will be dipping their toe in the water to see how they are likely to get on in the Assembly election — just using it to increase their profiles.”
CATNEY, Pat (SDLP)
DONALDSON, Jeffrey Mark (DUP)
LOVE, Alan (Ukip)
LUNN, Trevor (Alliance)
MCGEOUGH, Jacqui (Sinn Fein)
MORRISON, Samuel (TUV)
ORR, Jonny (Independent)
OSBORNE, Helen (Conservatives)
REDPATH, Alexander (UUP)
• Jeffrey Donaldson (DUP): 18,199
49.8%, down by 4.9% on 2005
• Daphne Trimble (UUP-Con): 7,713
21.1%, down 0.4%
• Trevor Lunn (Alliance): 4,174
11.4%, up 1.3%
• Keith Harbinson (TUV): 3,154
• B Heading (SDLP): 1,835
5%, up 1.1%
• Paul Butler (SF): 1,465
4%, down 3.5%
• Jeffrey Donaldson (DUP): 23,289
• Basil McCrea (UUP): 9,172
• Seamus Close (Alliance): 4,316
• Paul Butler (Sinn Fein): 3,197
• Patricia Lewsley (SDLP): 2,598
• Jeffrey Donaldson (UUP): 25,966
• Seamus Close (Alliance): 7,624
• Edwin Poots (DUP): 6,164
• Patricia Lewsley (SDLP): 3,462
• Paul Butler (Sinn Fein): 2,725