The Democratic Unionist Party’s (DUP) status as Westminster’s fourth largest party has not gone unnoticed – except perhaps by television broadcasters anxious to clinch election debates involving the leaders of much smaller parliamentary parties.

A legal challenge to the broadcasters’ contention that Northern Ireland is a place apart may fail – partly because, well, it is a place apart in its party lists. However, when the seemingly inevitable post-election trading begins, the region may have greater centrality.

The Conservatives or Labour might need the support of the DUP’s eight or, assuming the party wins back East Belfast from Alliance’s Naomi Long (probable, but no certainty), nine MPs. DUP members prefer the Conservatives by a ratio of seven to one over Labour (37 per cent favour neither) and back the party in areas such as Euroscepticism and tougher immigration controls. However, DUP voters include a sizeable section of working-class loyalists (not least in target East Belfast and vulnerable North Belfast) looking for better economic fortune and decent welfare policies. Cognisant of this, the DUP opposes, for example, the bedroom tax. DUP leaders want what they can get.

So the pleasant task confronting Nigel Dodds, Westminster DUP leader (Peter Robinson remains in overall charge despite being ousted as an MP in 2010) might be to open sealed bids from David or Ed for support short of formal coalition. The problem is that the financial plans for Nigel et al have already been made. Shortly before Christmas, the Stormont House Agreement was concluded between Northern Ireland’s main parties and the British government. Whilst the latter’s claim to be offering ‘additional spending power of almost £2 billion’ was risible – more than half was old money or loans – the deal was a significant financial package which the Conservatives or even less austere Labour might struggle to improve. Across the sectarian divide Northern Ireland’s parties have long been adept at spending other people’s money but the Oliver Twist approach must surely have its limits?

What else could be offered to the DUP? Here we enter controversial arenas. Most members (two-thirds) believe ‘homosexuality is wrong’ and that abortion should not be legalised (three-quarters oppose a relaxation of the current restrictions in Northern Ireland). Many of the party’s elected representatives supported devolved power-sharing with Sinn Fein in the 2006 St Andrews Agreement on the basis of the preservation of regional autonomy in matters such as abortion and gay marriage prohibition. Six of the party’s eight MPs belong to the very religiously conservative Free Presbyterian Church (only 3 per cent of Northern Ireland’s Protestants belong likewise)[1] so Westminster interference in these ‘moral matters’ is unlikely to be tolerated. Where activism from Westminster might be welcome is on the issue of parades. Half the DUP’s elected representatives belong to the Protestant Orange Order, stopped from marching adjacent to a nationalist part of North Belfast for the last two years. The DUP wants an independent commission to resolve this dispute. Would Cameron or Miliband concede this?

What of Northern Ireland’s other political parties? Sinn Fein can reasonably expect to defend their five seats, although the party’s majority is a precarious four votes in Fermanagh and South Tyrone. A superb election could net Foyle and North Belfast. Would Sinn Fein ever take seats at Westminster? For some Shinners, abstention is only a tactic, not a fundamental republican principle. Yet even within a much-changed party, swearing an oath of allegiance to a British Monarch might not be the easiest sell for the leadership. It would require a special ard-fheis (conference) decision with a two-thirds majority and is not on the immediate agenda. Even if a ‘countering the DUP at Westminster’ argument is considered, it may not be enough motivation for a party whose priority remains fixed on positions in government throughout the island of Ireland.

So no Ed and Martin (McGuinness) deal then. Where Miliband can look for solid backing is from the SDLP’s three MPs, who should all be returned. Given the SDLP is Labour’s sister party they are firm allies. The Liberal Democrats and Alliance are also sister parties – apart from the latter’s one MP who, problematically for the concept, sits on the Opposition benches. Also occupying those benches is Sylvia Hermon, an Independent seemingly certain to be returned and to offer continuing support to Labour.

We are often told these days that Northern Ireland is ‘open for business’. What seems certain is that, post-election, so will be its political parties.