One of the side-effects of a general election campaign fought in the long expectation of a hung parliament is that, for the first time in a very long time, the Northern Irish parties mattered.

A slip of the tongue by Labour allowed the Tories to put Gerry Adams, the effective life-President of Sinn Fein, onto their posters depicting Ed Miliband’s nationalist puppet masters. But it was the Democratic Unionists, who actually take their seats and were expected to take somewhere between eight and ten, who got most of the limelight.

Whether it was fighting to get into the TV debates or speaking out against EVEL in (of all places) The Guardian, the United Kingdom’s most right-wing parliamentary party got plenty of airtime.

The unexpected Conservative majority has denied the DUP the kingmaker role they might have hoped for, at least in the short term, but with a slender majority it seems prudent that David Cameron try to come to some arrangement with friendly MPs from our smallest home nation.

In that regard, the Northern Irish results will not have displeased Number 10, for unionism had a remarkably good night.

For starters, both of the major unionist parties – the DUP and smaller, more moderate Ulster Unionists – managed to increase their share of the vote whilst the two nationalist ones (Sinn Fein and the smaller, more moderate Social Democratic and Labour Party) lost ground.

In total the DUP and UUP added 1.5 points to their vote share whilst SF and the SDLP lost 3.6 points, to produce an overall increase in the margin between the two camps of over five points.

In particular the SDLP’s 2.6 point drop has called the leadership of Alasdair McDonnell into question, despite the party managing to hold on to all three of their Westminster seats. Indeed McDonnell came within a thousand votes of losing his own seat to the DUP.

Of course the UK doesn’t operate a proportional voting system, but this run of unionist success also extended into the realm of actual constituencies.

Going into the election the DUP had eight seats, Sinn Fein five, the SDLP three, the liberal and border-neutral Alliance Party one and Lady Sylvia Hermon, a Labour-sympathising Independent Unionist, the last.

Of particular concern to unionists was that Sinn Fein had been gradually gaining ground on Nigel Dodds, the DUP’s Parliamentary leader, in Belfast North. Its loss would leave the provincial capital without a Unionist MP following the shock defeat of Peter Robinson, the First Minister, in Belfast East by the Alliance last time.

(According to sources on the ground, one of the reasons the DUP ended up in this predicament is that the borders of the governmental entity of Belfast exclude large and heavily unionist suburbs in the east of the city).

As a result, the DUP and UUP struck a ‘Unionist Unity’ pact: the DUP would get a free run in Belfast North and Belfast East, whilst the UUP got a crack at two Sinn Fein seats, Fermanagh South Tyrone (FST) and Newry and Armagh. The local Tories also seem to have decided not to run in Belfast North or FST of their own volition.

This seems to have paid off handsomely: Dodds added more than three thousand votes to his slender 2010 majority of 2,224 as Sinn Fein slipped back; the DUP also recaptured Belfast East; and Sinn Fein’s majority in Newry and Armagh, whilst still substantial, was halved.

Most strikingly, UUP leader Tom Elliott managed to win FST from Sinn Fein. This was the UK’s most marginal constituency after 2010 when a pro-Conservative independent unionist fell just four votes short of winning. The UUP now have a majority of 530.

This large, rural seat is of huge psychological significance to unionism because of its transformative effect on the political map of Northern Ireland, and its loss is a setback to Sinn Fein’s ongoing attempts to ‘green the west’.

The UUP also managed to win South Antrim from the DUP, increasing their Westminster cohort to two. The once-dominant party of Northern Irish unionism disappeared from Parliament in 2010 when Lady Hermon, a left winger, defected over the ill-fated Conservative-UUP alliance.

Hermon comfortably held her solidly unionist seat this time, taking almost 50 per cent of the vote.

As a result of the election, unionists now represent 11 of the province’s 18 Westminster constituencies, including a reassuring splash of pale blue in the Union’s westernmost seat. Moreover the DUP came within 1,000 votes of recapturing Belfast South, and the results suggest that a single unionist candidate could take Newry & Armagh in a good year.

To have gone from the fear of no unionist MPs in Belfast to almost taking three will be particularly cheering, although it may make the SDLP more receptive to Sinn Fein offers of a pact next time.

The result is also fairly good news for David Cameron. Hermon might as well be a Labour MP (and perhaps would be, if they stood there) but the remaining ten unionist MPs are all on the political centre-right and likely to support the Government (for a price) if needed.

He will also welcome the return to Parliament of the UUP (in the absence of actual Conservatives), a party with historical ties to the Tories and with whom his party has more in common. In particular Danny Kinahan, the new MP for South Antrim, is reported to harbour Tory sympathies.

It remains to be seen whether this sunny prospect will last. The previous boundary review – which included cutting the number of MPs by 50 – would have cut the province’s representation to 16 seats to the expected benefit of nationalism. Without the seat cut, however, it seems likely that any changes will be less dramatic.

Northern Irish nationalists meanwhile find themselves in the same boat as their Welsh counterparts: in gentle decline, trying to figure out how the SNP does it. Sinn Fein in particular will be worried by the very strong performance of the far left Irish party People Before Profit in Belfast West, whose candidate professed himself ‘neither unionist nor nationalist’. The SF vote dropped by a remarkable 16.4 points here.

In fact the Republicans fell back in all their remaining constituencies: by 3.3 and 4.9 points respectively in the ultra-safe constituencies of Mid Ulster and West Tyrone, and by just short of a point in unionist-targeted Newry and Armagh.

Meanwhile the SDLP, in addition to almost losing their leader, saw their vote drop by more than six points in South Down, although they managed to extend their lead over Sinn Fein in Foyle.

A brief, final word on the mainland parties. The NI Conservatives were nowhere this election, but UKIP managed 2.6 per cent of the vote (ahead of the local Traditional Unionist Voice party), and may have set themselves up to win one or two seats in the Northern Ireland Assembly next year from East Antrim and South Down.

Northern Ireland Results 2015 Election