Ms O'Neill, Sinn Fein's Stormont leader, said there was "no rhyme or reason" for the Democratic Unionist Party (DUP) to stay away from government now that negotiations over the Northern Irish protocol were "complete".

Her words come after counting concluded in Northern Ireland's council elections, with Sinn Fein becoming the largest party in local government for the first time.

After a two-day count, they emerged with 144 seats, an increase of 39 on the last vote in 2019.

Ms O'Neill described the results as "momentous", adding: "The onus is now on the British and Irish governments to get together and focus their efforts on the immediate restoration of the executive and assembly.

"We expect to see an early meeting of the British Irish Intergovernmental Conference. The boycott of the assembly cannot go on, and an executive must be formed."

She added: "All the while when the DUP stay out of the executive and the assembly public services are suffering, the public are suffering because of austerity, because of cuts that are coming directly from London.

"It is not a tolerable situation, there shouldn't be any more delays and I want to see a plan on the table as to how we are going to get back around the table to make politics work and to have a locally-elected assembly."

The DUP was the largest unionist party with 122 seats - the same number as four years ago - while the Alliance Party increased its representation by 14 seats to 67.

DUP leader Sir Jeffrey Donaldson said: "I think [...] there are lessons to be learned for unionism in its broadest sense. The DUP has had a good election but unionism needs to do better, we need to be winning more seats.

"I'm happy to sit down with my fellow unionists and examine these issues and how greater co-operation can lead to a pathway towards more success for unionism in general."

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Significant losses for other parties

The Ulster Unionists and the SDLP both suffered significant losses, however, with the UUP winning 54 seats and the SDLP 39.

UUP leader Doug Beattie said he was disappointed but had no plans to resign, adding: "I made it quite clear that the party elected me, and I am the party leader, and I am going absolutely nowhere. It'll be the party that decides my fate one way or the other.

"So those people who are a little bit shaky because we've had a bad election, they can stay shaky because I'm on absolutely rock solid foundations, and I'm going nowhere."

SDLP leader Colum Eastwood said Sinn Fein had "cannibalised" the nationalist vote.

"It has been very clear when we have been speaking to people that people are really annoyed at the DUP, that they want the executive back up and running, and they wanted to send a message," he said.

"Sinn Fein asked them to send that message, and they sent it."

Smaller parties and independents took the remaining 36 seats.

There are 11 councils in Northern Ireland - Sinn Fein will be the largest party in six local government areas, including Belfast, while the DUP will have the largest representation in five councils.

Sinn Fein secured 30.9% of first preference votes, ahead of the DUP on 23.3%, 13.3% for Alliance, 10.9% for the Ulster Unionists and 8.7% for the SDLP.

The turnout was 54%.