If current polling trends in Scotland are confirmed on 7 May, this election could result in the biggest challenge to the Union since the formation of the Irish Free State.
As a consequence the electoral fortunes of the Democratic Unionist Party and Ulster Unionist Party are of more significance than at any time in recent history.
A good result for the two main unionist parties would see the UUP winning in Fermanagh and South Tyrone and the DUP holding its present seats and winning back East Belfast.
From a party perspective, the DUP, apart from wanting to hold East Belfast, will be hoping that the Reverend William McCrea can hold on in South Antrim and that David Simpson can hold off the challenge from the UUP’s Jo-Anne Dobson in Upper Bann.
For Mike Nesbitt there is a lot hanging on the UUP returning at least one MP.
On the back of some signs of a comeback in the last local government elections, this would prove, in his words on BBC Talkback earlier this week, that the UUP are not “yesterday’s people”.
Failure to win a seat will once again raise the issue of whether the party has a long-term future outside of a fusion with the DUP.
However, the UUP position is far from hopeless. Tom Elliott will be pleased with fact that the other unionist parties are out canvassing for him, as it must be a concern that more hard-line DUP and TUV supporters will stay at home on election day.
Both parties’ manifestos share an emphasis on improving Northern Ireland’s economic performance by lessening dependence on the public sector and on the protection and improvement of public services.
This and the electoral pact has served to blur any differences of principle between the UUP and DUP.
There was a muted reference to its historic differences with the DUP in the UUP’s manifesto mention of the election as “an opportunity to stop voting out of fear, because people say bad things will happen to you if you do not support them”.
In fact, perhaps one of the most noticeable things about the election campaign is how little the politics of fear has featured. In part this is because Sinn Fein’s abstentionism removes them as any sort of post-electoral threat at Westminster.
Professor Jon Tonge noted in his recent book on the party that the present DUP is much-changed from its original Paisleyite creation.
However, its abrasive ‘blood and thunder’ past lingers on in what Tonge refers to as “remnants of older discourses”.
It was this that perhaps led the former Ulster Unionist/Tory candidate in the constituency, Trevor Ringland, to declare that he could not vote for the DUP candidate in East Belfast.
Such concerns will have been reinforced by Jim Wells’ recent comments on same-sex relationships and child abuse, although his resignation will deflate the issue somewhat.
Peter Robinson has been working since the 1980s to transform the DUP into a more mainstream, less religiously strident party – his recent declaration of a free vote for his MLAs on the proposal to legalise terminations in cases of fatal foetal abnormality can be seen as part of this approach.
Gavin Robinson personifies the modernising wing of the party and its desire to detoxify its image amongst the Protestant middle class.
More generally, the DUP’s overwhelming focus on the strong leverage the party could have in the event of a hung parliament and the danger to the Union represented by the SNP may enhance its appeal to UUP voters in some key constituencies and energise the ‘garden centre Protestants’ into voting.
It will be interesting to see if this strategy can buck the trend of declining electoral turnout amongst Protestants or whether a widespread cynicism about the performance of our devolved institutions and Wells’ reminder that Paisleyism hasn’t gone away will be reflected in the results in May.
The TUV is standing in only seven constituencies, mostly in the overwhelmingly unionist areas in the east of the Province.
The party only needs to do modestly well to beat its disastrous Westminster performance of 2010, after which it appeared to come close to folding.
It also did badly in the 2011 elections, but fared much better last year in both the local and European elections.
• Henry Patterson is Emeritus Professor of Irish Politics at University of Ulster