By Mark Devenport
BBC NI political editor
In days gone by, it was sometimes said that you could put a donkey up in certain parts of Northern Ireland and pin an orange or green rosette on it, with a fair degree of certainty the animal would get elected.
But the 2010 Westminster election promises to be different, hosting intriguing contests in some seats which have long been considered foregone conclusions.
The potential clashes fall into three broad categories - contests between unionists, struggles between nationalists and places where the communities are evenly divided and a seat could go either way.
Sir Reg Empey is standing in South Antrim
Within unionism probably the greatest build-up has been given to the fight in North Antrim between the DUP's Ian Paisley Jnr. and the Traditional Unionist leader Jim Allister.
During the long tenure of Ian Paisley Senior, North Antrim would never have been described as a "marginal".
However Mr Allister, a former DUP MEP, is now the standard bearer for unionists who remain opposed to sharing power with Sinn Fein.
His 66,000 votes in last year's European election carved off about a third of the DUP's support base and informal tallies taken during the count put him in the lead in North Antrim.
The question will be whether that showing will carried over into a Westminster election.
Ian Paisley Junior has been at pains to contrast the DUP's positive record on power sharing with what he would describe as the relentless negativity of the TUV.
So Northern Ireland will be treated to a new spectacle - an election in which a Paisley is fighting, but it is his opponent who is standing on on a "never, never, never" ticket.
Next door the South Antrim constituency should see the tightest fight between the DUP and the Ulster Unionists, in their new electoral alliance with David Cameron's Conservatives - the Ulster Conservatives and Unionists (UCU).
The DUP's William McCrea took the seat from the Ulster Unionists in a by-election in 2000.
David Burnside won it back in the general election the following year, but lost it again in 2005. However Mr McCrea's majority of around 3,500 is far from impregnable, and by default the UCU have ended up with a well known name in the Ulster Unionist leader Sir Reg Empey.
Lady Sylvia Hermon is standing as an independent
Sir Reg entered the fray after a row over the UUP's original choice of local candidate and his Chris Grayling-like views on gay bed and breakfast guests.
As a Stormont minister, Sir Reg has a high profile, however as an outsider and late entrant he will have to work hard to get his campaign in South Antrim off the ground.
In South Antrim and elsewhere the TUV could turn out to be "king makers" if they deprive the DUP of enough votes to let the Conservatives and Unionists in.
Others seats where the UCU may hope to make inroads on the DUP include Upper Bann and Strangford, the constituency of the former MP Iris Robinson who stepped down in the wake of a scandal over her sexual and financial dealings.
The UCU have a celebrity candidate in Strangford in the former UTV and BBC presenter Mike Nesbitt.
Whilst public concern over Iris Robinson's conduct may be a factor the DUP has a 12,000 majority and a popular local candidate in Jim Shannon. So Mr Nesbitt will need all his name recognition to close the gap.
DUP leader Peter Robinson is standing in East Belfast
Whilst the Conservatives and Unionists may hope to build in some areas, in the only constituency they used to hold, North Down, they face a major problem.
Their Ulster Unionists' outgoing MP Lady Sylvia Hermon was close to Labour in the last parliament and resisted all attempts to persuade her that the Tory link was a good idea.
The Conservative and Unionist candidate Ian Parsley will hope that North Down voters will focus on the UK wide choice between David Cameron and Gordon Brown, who Lady Hermon supports.
But the DUP's decision to stand aside will assist Lady Hermon, who is so popular in North Down that one caller told a BBC Radio Ulster show he would vote for her if she was "standing for Al Qaeda".
Also within the mainly unionist terrain, there's East Belfast where the DUP leader Mr Robinson has angrily rejected what he terms BBC "smears" about his land deals and his handling of his wife's conduct.
At one stage last year, Mr Robinson suggested he might give up on Westminster to concentrate on Stormont.
But now he says he will be the exception holding on to both his MP and MLA roles, whilst his colleagues will give up so called "double jobbing".
Although Mr Robinson must remain favourite to defend his seat, the Conservatives and Unionists will harbour hopes for their candidate, former Ireland rugby international Trevor Ringland, whilst East Belfast is also the place where Alliance is talking up the chances of its deputy leader, Belfast Mayor, Naomi Long.
SDLP's Mark Durkan is standing in Foyle
So far as the nationalist seats are concerned, the contest seems more predictable than the many unionist dog fights.
Notwithstanding questions over his handling of sexual abuse allegations concerning his brother and very serious charges regarding his role in IRA murders of the "disappeared" during the troubles, Gerry Adams is likely to be one of the first elected in his West Belfast seat. Most of his Sinn Fein colleagues should also be safe.
In Foyle the former SDLP leader Mark Durkan faces a challenge from former IRA prisoner and MLA Martina Anderson. But he should be able to defend his 6,000 majority.
The toughest battle is likely to take place in South Down where the new SDLP leader Margaret Ritchie is seeking to succeed her political mentor the outgoing MP Eddie McGrady.
She will "double job" if elected, but will give up her Stormont ministerial portfolio. Ms Ritchie faces a challenge from the Stormont education minister Caitriona Ruane.
Eddie McGrady had a 9,000 majority over Ms Ruane in 2005. The balance between the two parties was much closer in the 2007 Assembly elections, when Ms Ruane topped the poll.
Sinn Fein's Caitriona Ruane is standing in South Down
However unionists in South Down reckon the controversial nature of the Sinn Fein minister's handling of her education brief may encourage some of their supporters to vote tactically for the SDLP.
Finally there are two seats where the demographic balance between unionists and nationalists is so close that it has encouraged discussion of unionist pacts to oust the outgoing nationalist MPs.
In Fermanagh and South Tyrone this has led to a UCU U turn, ditching David Cameron's pledge that the new force would fight every seat in favour of a unionist unity candidate in the independent former Chief Executive of Fermanagh council, Rodney Connor.
The DUP has also stood aside in favour of Mr Connor.
In the last election there were 22,925 unionist votes in Fermanagh, compared to 25868 nationalist votes.
If the outgoing MP Michelle Gildernew is able to severely squeeze the SDLP's celebrity candidate former journalist Fearghal McKinney, then she may hold on against what she describes as a "sectarian" pact.
But if she can't Rodney Connor could go to Westminster where, having pledged to take the Conservative whip, he could potentially help David Cameron become Prime Minister.
The other seat where pacts have been discussed is South Belfast which the SDLP's Dr Alasdair McDonnell took from the Ulster Unionists in 2005.
The DUP and the local Orange Order have called on the UCU to stand aside for an agreed candidate who could take the seat back for unionism.
But one obvious difference is that whilst Michelle Gildernew stands on an abstentionist platform Alasdair McDonnell takes his seat.
The local UCU candidate Paula Bradshaw says any agreed candidate should have what she describes as "the same cross-community credentials and record of service to the community" as demonstrated by Rodney Connor in Fermanagh.
So far, with the clock ticking to the opening of nominations, there is no sign of South Belfast following the Fermanagh model.