A Sinn Fein minister has said her party is not interested in last-ditch negotiations with the Democratic Unionists to save the coalition government and avert a snap election in Northern Ireland.
Health minister Michelle O'Neill said the UK Government needs to press ahead and call the poll.
After meeting Northern Ireland Secretary James Brokenshire at Stormont House in Belfast, Ms O'Neill said: "We made very clear to James Brokenshire in terms of what we believe needs to happen and what needs to happen next is an election.
"We are not interested in trying to get into negotiations now - what we need is fundamental change. We believe the public need to have their say."
DUP leader and former first minister Arlene Foster has indicated she would be open to talks with her former partners in government.
On Tuesday evening, Prime Minister Theresa May and Irish premier Enda Kenny discussed the crisis on the phone.
They pledged to work together to find a way through the political storm that has threatened devolution.
The collapse of the institutions was triggered by the resignation of deputy first minister Martin McGuinness on Monday.
The Sinn Fein veteran's move, in protest at the DUP's handling of a botched renewable energy scheme, forced Mrs Foster from her post as first minister.
The region faces the prospect of direct rule from Westminster being reintroduced if the fallout between the DUP and Sinn Fein cannot be resolved on the other side of an election.
While the looming collapse of power-sharing was triggered by the Renewable Heat Incentive (RHI) affair - a scandal that has left Stormont with a £490 million bill - other disputes between the two main parties have been reignited by the furore.
Ms O'Neill said: "It's now time for the electorate to have their say, it's now time for the electorate to make judgment on the DUP's arrogance.
"W hat the DUP have displayed over the last months and years is a lack of respect towards women, the LGBT community, the Irish language community, ethnic minorities. These institutions have to have equality."
Following Mr McGuinness's resignation, Mrs Foster announced plans for a public inquiry into the RHI.
Ms O'Neill branded that initiative "too little, too late".
Sinn Fein president Gerry Adams struck a different tone as he addressed the media in Dublin, saying: "We are always open for talks and we are always open to meet. Of course we are."
A Downing Street spokesman said, in Tuesday evening’s phone conversation, Mrs May and Mr Kenny “recognised the difficulties and seriousness of the situation in Northern Ireland and how important it was to work together - with the Irish Government and the parties of Northern Ireland - to find a solution.
“In addition, they spoke about how the Northern Ireland Secretary and the Irish Minister for Foreign Affairs and Trade, Charlie Flanagan, will be working very closely together over the next few days and months to support the parties of Northern Ireland in finding a resolution.
“The Prime Minister also said how important it was to make sure that Northern Ireland’s voice and interests are heard as we prepare to leave the European Union and how the Northern Ireland Secretary is fully committed to making this happen.
“She added that it was still our intention to hold a Joint Ministerial Committee at the end of the month to bring the devolved nations together in getting the best deal for the whole of the United Kingdom.”
At Prime Minister’s Questions in the House of Commons, Mrs May rejected a challenge from Scottish National Party Westminster leader Angus Robertson to postpone the start of EU withdrawal talks under Article 50 until after the crisis in Northern Ireland is resolved.
Mr Robertson urged the PM not to “plough on regardless” at a time when there may be no Northern Irish ministers available to participate in JMC discussions.
The PM’s official spokeswoman later said that she understood Stormont ministers would continue to hold their positions in a caretaker role during any election.
The spokeswoman added: “Obviously the situation is in flux and we are doing all we can to try to find a way through, including by the PM speaking to the Irish Taoiseach last night about the situation.
“There is now a window before elections could be called, and we are not going to get ahead of ourselves. We have been clear on the timetable for triggering Article 50 and we will be sticking to that.”
She added: “We are going to focus on how we can support political stability in Northern Ireland, recognising the progress that’s been made and not wanting to put that at risk and engaging with all the parties.”