FOYLE: With the departure of former SDLP leader John Hume from Westminster, a lot is riding on his successor Mark Durkan’s ability to hold onto this Derry-based seat.
Mr Durkan faces a strong and determined challenge from Sinn Féin`s general secretary Mitchel McLaughlin, knowing republicans reduced the SDLP`s 11,550 Westminster lead to 1,532 votes in the 2003 Assembly election.
In this do or die contest, defeat for Mark Durkan will make him vulnerable to a leadership challenge while a loss for Mitchel McLaughlin could postpone his day in the sun.
UPPER BANN: If a lot is riding on Mark Durkan’s ability to hang onto Foyle for the SDLP, defeat for David Trimble could have major implications for him and the Ulster Unionists.
The UUP leader was forced to a recount in 2001 by DUP challenger David Simpson and was jostled outside the count centre. However he won comfortably enough with a 2,058 majority.
However four years on, Upper Bann has become even more of a dogfight with Mr Simpson now enjoying a higher profile as Mayor of Craigavon and his party just 386 votes behind the UUP in the Assembly contest.
EAST ANTRIM: For years Sammy Wilson has carved out a reputation as an amusing if bigoted member of Belfast city council.
Now he hopes to make his mark at Westminster but must first of all overcome veteran Ulster Unionist MP Roy Beggs, a politician who has proven adept at seeing off DUP pretenders to his throne beating Jim Allister in 1983 and Nigel Dodds nine years later.
This is a rematch of the 2001 contest, where Mr Beggs squeaked home with a 128 majority. However DUP hopes of taking the seat were boosted in 2003 when the party outpolled the Ulster Unionists by 1,680 votes.
SOUTH ANTRIM: Round three in the battle between Ulster Unionist MP David Burnside and DUP veteran, the William McCrea promises to be another gruelling contest.
In 2000, Mr McCrea captured the seat for the DUP in a by-election, defeating Mr Burnside by 822 votes, but his reign was short-lived with the UUP`s candidate regaining the seat one year later with a 1,011 majority.
Mr Burnside will hope his tough rhetoric and attempts to distance himself from David Trimble will be enough to keep the DUP at bay but he will be mindful that his rivals outpolled the UUP two years ago in the Assembly Election by 298 votes on a lower turnout.
SOUTH BELFAST: The retirement of Ulster Unionist MP, Martin Smyth has provided former Stormont Culture Minister Michael McGimpsey with a chance to realise his dream of sitting on the Westminster benches.
However with unionists unlikely to agree a pact, both SDLP deputy leader Dr Alasdair McDonnell and Sinn Féin’s Alex Maskey will hope to capitalise on a split vote and become the constituency`s first ever nationalist MP.
The 2003 Assembly election was tight and much could depend on the 2,150 votes secured by the Women’s Coalition`s Monica McWilliams in 2003.
FERMANAGH AND SOUTH TYRONE: Michelle Gildernew’s spectacular victory for Sinn Féin with a wafer thin majority of 53 left many unionists reeling after the 2001 General Election.
The Sinn Féin MP benefited from a split unionist vote and despite warning it should never happen again, it looks like the UUP and DUP will be unable to agree a pact. The SDLP are also set to stand again, but republicans will really to defend the seat once held by Bobby Sands on the anniverary of his death on hunger strike.
Sinn Féin will urge nationalists to consolidate their vote behind Ms Gildernew if a compromise unionist candidate emerges.
WEST TYRONE: The poll topping performance of Carrickmore GP, Dr Kieran Deeny in the 2003 Assembly Election caught some by surprise and represented a breakthrough for indepedent candidates.
Dr Deeny secured cross community backing for his campaign to secure an acute hospital for Omagh but was disappointed when the SDLP chose not to give him a clear run at Sinn Féin vice president Pat Doherty’s seat.
Both Deeny and the SDLP candidate will have their work cut out to overturn Doherty’s majority.
EAST BELFAST: This constituency has been a DUP fortress since its deputy leader Peter Robinson first won the seat in 1979.
However Ulster Unionist strategists believe former Stormont Economy Minister Sir Reg Empey is capable of causing an upset, noting the DUP was just 1,880 votes ahead of them in the 2003 Assembly election.
DUP strategists are unruffled, believing the former Stormont Regional Development Minister has the mettle to comfortably see off the Ulster Unionist’s challenge.
LAGAN VALLEY: Jeffrey Donaldson faces his first electoral test as a Democratic Unionist, having jumped ship last year from the UUP after years of feuding with David Trimble.
The constituency has always been an Ulster Unionist preserve but Jeffrey Donaldson believes those who voted for him will also make the transition to the DUP.
UUP strategists were denied their dream of another Donaldson versus Trimble showdown when their leader’s wife, Daphne failed to secure the party nomination. They are pinning their hopes instead on businessman and electoral newcomer Basil McCrea.