There has been some discussion about which main GB party Northern Ireland parties may back in the event of a hung parliament (i.e. a parliament with no overall majority for a single party). The discussion is welcome in that it hints at a focus on issues, but it is entirely misplaced.
It was none other than Ian Paisley (senior) himself who said, in 1992 when a hung parliament looked likely, that a government to be stable requires a “majority of 20”. If anything this proved to be an underestimate – the Conservatives secured a majority of 21 but had in fact lost it (through defections and by-elections) in four years. Still, a typical parliament would indeed see a majority of 20 suffice – but not much less (the current Conservative/LibDem coalition was elected with a majority of 76 but as dissolution had a majority of 62).
So, although in theory 326 seats is the target (323 if Sinn Féin holds at least four seats and the Speaker is re-elected), just scrambling to such a figure would not be sufficient for a stable government. The target is in fact to get to the mid-330s, and even then it is highly risky if a coalition or confidence/supply arrangement requires more than two parties (any of which could walk away at any moment). A parliament where no two parties can get to at least 330 will mean the parliament does not go full term, and may indeed require another swift election (as in 1974).
This means, in practice, Northern Ireland parties cannot possibly win enough seats to be relevant to the outcome, as they simply will not make the difference between scrambling to a majority on one hand, and a majority sufficient to go anything like full term on the other. Realistically, the very best they could do would be to give backing to one “Emergency Budget” followed by a second election – a fairly thankless task for parties used to playing a permanent Opposition role (even when they old 3 or 4 Executive seats in a devolved legislature!)
That does not mean Northern Ireland parties will not have a role. In a parliament operating by confidence/supply, they could be the difference between a referendum on the EU and no referendum, for example (issues where even the big parties may see some splits), or military intervention or no military intervention (as the tight vote against it in Syria showed).
In practice, the people of Northern Ireland need to elect MPs who will make a difference lobbying or arguing a case at Westminster on its merits. The fact, when discussing possible post-election deals, no one there appears even to have heard of Nigel Dodds is perhaps cautionary…