The Northern Ireland Assembly has failed to elect a new Speaker after the DUP said it would not support the process.
The devolved administration is now unable to function after the election last week, which saw Sinn Fein emerge as the largest party for the first time.
Sir Jeffrey Donaldson, the leader of the DUP, said his party’s refusal was part of a protest against the Northern Ireland protocol.
He said he is sending a “clear message” to the EU and UK government about resolving problems with the post-Brexit trading agreement.
Sinn Fein’s leader said she would meet with Prime Minister Boris Johnson when he travels to Northern Ireland on Monday.
Michelle O’Neill said she would tell him to stop pandering to the DUP.
She also accused Sir Jeffrey of “denying democracy” and said his action “isn’t tolerable, it isn’t acceptable, it isn’t good enough”.
She said the DUP has “punished the electorate” and that “the public deserve better”.
Naomi Long, the leader of the Alliance Party, said she was “appalled” by the DUP’s behaviour.
“Despite the fact that the vast majority of people in Northern Ireland voted for parties that wanted to return to government, that wanted to see the Assembly work, and despite the fact that even those who voted for the DUP gave them no mandate to block a return to the Assembly, we have found ourselves in that situation today,” she said.
“But while this is a sad day for the people of Northern Ireland, it is a shameful day for the DUP.”
DUP: ‘We need decisive action’
The DUP has also said it will refuse to nominate for the position of deputy first minister, which would block the formation of a new executive.
The new first minister-elect cannot take up the role without the DUP nominating a deputy first minister.
Under Northern Ireland’s devolved power-sharing system, both roles are equal and one cannot be in office without the other.
The 90 MLAs elected last week had met for the first time since the election at Stormont, where two candidates were nominated for Speaker – Mike Nesbitt of the UUP and Patsy McGlone of the SDLP.
Neither received the necessary support.
Sir Jeffrey said it was time for Mr Johnson to outline what he intended to do to advance negotiations with the EU.
“I believe that we need to send a very clear message to the European Union and to our government that we are serious about getting this protocol sorted out – because of the harm it is doing, undermining political stability, damaging the agreements that have formed the basis of political progress made in Northern Ireland, to our economy, contributing to the cost of living crisis – this matter needs to be dealt with,” he said.
“While others sit on their hands we are not prepared to do that. We need decisive action taken by the government.”
Unionists like the DUP oppose the protocol, arguing the Irish Sea border threatens Northern Ireland’s place in the United Kingdom.
The two main nationalist parties, Sinn Fein and the SDLP, support it as it prevents a hard border on the island of Ireland.