BELFAST (Reuters) - The pro-British Democratic Unionist Party narrowly remained Northern Ireland’s largest party after edging Irish nationalists Sinn Fein by a single seat in snap elections ahead of arduous talks to resurrect their power-sharing government.

Arlene Foster, leader of the DUP, arrives at a counting centre for the Northern Ireland Assembly elections in Omagh, Northern Ireland, March 3, 2017. REUTERS/Toby Melville

Voters turned out in their highest numbers in two decades on Thursday in the first regional election in the United Kingdom since its vote to leave the European Union as nationalists who favour a united Ireland and unionists who want the province to remain British jostle for influence.

The DUP won 28 of the 90 seats as a surging Sinn Fein almost wiped out the 10-seat advantage the DUP secured in elections a year ago. Just over 1,000 votes split the main parties from the 800,000 ballots cast in the closest ever assembly election.

“Let us now move forward with hope, hope that civility can return to our politics,” outgoing first minister Arlene Foster of the DUP told supporters after her re-election on Friday. “There is work to be done to quickly mend the relationship which has been frayed by the discord of this election.”

Foster’s conciliatory tone after her party’s disappointing result was in stark contrast from an acrimonious campaign where, despite pleas from Dublin and London to avoid a further souring of relations, the two parties rallied their sectarian bases.

Sinn Fein’s leader Michelle O’Neill told journalists it was an “amazing day” as her party benefited from a jump in turnout to 65 percent, the highest since the first elections immediately after the 1998 Good Friday peace agreement.

It was the closest nationalists, traditionally backed by Catholics, had ever come to becoming the largest party in the Protestant-majority province. Unionists candidates, who tend to be favoured by Protestants, captured less than half of the seats for the first time.

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The DUP’s failure to win at least 30 seats also means it no longer has the power to veto legislation on its own, something the conservative party has done to block extending gay marriage to the province.

POWER-SHARING

The two largest parties will have three weeks to form a new power-sharing government to avoid devolved power returning to the British parliament at Westminster for the first time in a decade.

But with relations at their lowest point in a decade, Sinn Fein insists among its demands for re-entering government that Foster must step aside while months of investigations begin into a botched green energy scheme she established.

The former political wing of the Irish Republican Army, who accused the DUP of not treating it as equals before collapsing the previous administration in January, will be further buoyed by their strong showing.

“The prospect of a devolved government being formed, which was already slim anyway, is very remote. I just don’t see it happening,” said Jon Tonge, professor of politics at Liverpool University.

No one predicts the impasse will bring a return to the violence that killed 3,600 people in the three decades before the peace agreement.

But some are warning there could be a deterioration in community relations coupled with government paralysis, as Brexit talks determine the province’s political and economic future.

Sinn Fein President Gerry Adams said he could not guarantee that the return of Northern Ireland’s 1.8 million people to direct rule from London could be avoided.

“That would be a total failure of the politicians of Northern Ireland,” Peter Hain, the last British minister for Northern Ireland to oversee direct rule in 2007, told Sky News.

“To effectively hand power back to London would I think be a disaster for devolution and a serious setback for progress in Northern Ireland.”