Sinn Fein has become the first nationalist party to win the most seats in the Northern Ireland Assembly in its 101-year history.

Voters flocked to the polls to elect 90 new members of the Legislative Assembly, with Sinn Fein winning a lion’s share of the seats.

As counting concluded in the early hours of Sunday morning, the final results showed Sinn Fein with 27 seats, pushing the Democratic Unionist Party (DUP), which has 25, into second place.

Michelle O’Neill, the party’s vice president, is now set to become the country’s first nationalist first minister.

Speaking earlier in her declaration speech in Magherafelt, Ms O’Neill said: “Today represents a very significant moment of change.

“Today ushers in a new era which I believer presents us all with an opportunity to reimagine relationships in this society on the basis of fairness, on the basis of equality and the basis of social justice.

“Irrespective of religious, political or social backgrounds my commitment is to make politics work.”

Nicola Sturgeon, the Scottish first minister, congratulated Sinn Fein’s leader Mary Lou McDonald and Ms O’Neill on a “truly historic win”.

The DUP lost support among unionists over its response to Brexit and trading arrangements concerning Northern Ireland and this caused a split of votes between the country’s three unionist parties.

Stormont is reliant on power-sharing between the nationalist parties (those who want Irish unity) and the unionists (those who want Northern Ireland to remain part of the UK) and the DUP has previously indicated it could boycott the government, rather than see a nationalist first minister.

Northern Ireland secretary Brandon Lewis said he is encouraging the parties to form an executive as soon as possible.

He said the people of Northern Ireland deserve “a stable and accountable local government”.

Mr Lewis added that in the coming days he will meet with all party leaders and will urge them to restore the Stormont institutions “at the earliest possible moment”.

Previously the biggest party in Stormont, the DUP resigned from the first minister role in February in protest at the Northern Ireland Protocol.

Because of the power-sharing rules, the move forced Ms O’Neill to also step down.

DUP MP Ian Paisley said there would be no devolved government in Northern Ireland while issues around the Northern Ireland Protocol remain unresolved.

Read more:
What is power-sharing in Northern Ireland?
Who is Sinn Fein’s deputy leader Michelle O’Neill?

Speaking at an election count centre in Jordanstown on Friday, Mr Paisley said: “I think the elephant in the room is the protocol.

“Until we get this matter fixed we can have whatever election we want but there is not going to be a government until we get that protocol issue resolved.

“Hopefully today will be a focus for the government that they have to now resolve this, not just for unionists but for everyone. The protocol hurts us all.”

The deadlock will increase tensions between Westminster and Brussels, with the UK insisting all options remain on the table – including the possibility of unilaterally scrapping elements of the post-Brexit deal.

That could trigger a major breakdown in relations between the UK and European Union.