THERESA MAY was presented with another political bear trap last night – following Brexit and the threat of a second Scottish independence referendum – when Sinn Fein came within one seat of drawing level with the ruling Democratic Unionist Party in the Northern Ireland Assembly elections.

The Prime Minister will now have to deal with three constitutional crises: resurgent republicanism across Irish Sea, the push for a second independence referendum in Scotland, and the uncharted land of a post-Brexit Britain.

The Stormont result means that the DUP, who won 28 seats – one more than Sinn Fein – are unlikely to be able to muster the 30 votes necessary to block reforms over same sex marriage and Ulster's anti-abortion laws. But for May it also means that with the endorsement of Sinn Fein and the other nationalist party, the SDLP who took 12 seats, there is a strong and vociferous majority in the north of Ireland for remaining in the EU.

Following the result Sinn Féin declared the Unionist majority "demolished" in Northern Ireland. The party said it now had a "clear mandate" to take forward discussions about how best power sharing could be agreed.

Although the DUP entered the election 10 seats ahead Sinn Féin, the republicans finished just a hair's breadth behind the DUP with 1,168 fewer first preference votes.

The two parties now have three weeks to establish a government. Northern Ireland's power-sharing agreement decrees that government must be run by Irish nationalists and unionists together – and if a government cannot be formed in that timeframe another election will be called.

The election was called after the collapse of a coalition led by Arlene Foster's DUP and Sinn Féin's Martin McGuinness in January this year.

The results mean the DUP no longer has the number of seats it needs to veto progressive reforms, having slipped below the 30 seats required, although notionally they could ally with rivals the Ulster Unionist Party which won 10 seats. Sinn Fein has pushed for Northern Ireland to bring in marriage equality and abortion in specific, restricted cases. Both are currently illegal.

At a press conference yesterday afternoon Sinn Féin President Gerry Adams said: "The notion of a perpetual Unionist majority has been demolished. We need to reflect on that but so do the leaders of Unionism, and everyone on this island, and this part of the island. We have been given a clear mandate. We intend to assert that mandate and be true to the commitments we have made."

Speaking outside the party's West Belfast office, Adams said Sinn Fein was keen to ensure powersharing in the region is restored as soon as possible in negotiation with other leaders. But he again insisted that the party will not support DUP leader Arlene Foster as Northern Ireland's First Minister until she has been cleared of any wrongdoing related to the Renewable Heat Incentive (RHI) scandal, the failed energy scheme that is set to cost the public purse almost £500 million. An inquiry is ongoing.

Adams added: "Our position is very straightforward. We will not be consenting to Arlene Foster being First Minister until this issue is cleared up." He claimed that he would instead nominate Michelle O'Neill, SF leader.

O'Neill said that formal discussions would start on Monday. "The task is not easy, but it is achievable if people come at it with the right attitude...On Monday morning I will lead our team into the Assembly where we are ready to deal with all the issues."

The SDLP fared better than expected and replaced the Ulster Unionist Party, which won just 10 seats, as the third largest party in the Assembly. The dramatic shake-up led Ulster Unionist leader Mike Nesbitt to announce his resignation. The Alliance Party took eight seats, and the Greens won two.

But although Sinn Fein has put pressure on Arlene Forster to stand down, DUP MP Jeffrey Donaldson insisted there is no question over her future as party leader despite the disappointing performance.

However according to Northern Ireland political commentator Jude Collins, the DUP is now "standing on thin ice". He added: "The bogeyman Sinn Féin is now so close, they can feel hot breath on their collar. That should inject a note of courtesy into their dealings with the republican party. If you have a death-wish, of course, you won’t change a thing."