Gordon Brown meets Sinn Féin president Gerry Adams today for talks to try to ensure devolution in Northern Ireland does not collapse.
Mr Adams is going to Downing Street amid mounting speculation Sinn Féin could derail the smooth transition of power from the Rev Ian Paisley when he steps down as First Minister on Thursday.
Peter Robinson, the East Belfast MP who took over as leader of the Democratic Unionist Party on Saturday after one of the longest apprenticeships in history, could have his elevation to the pinnacle of Northern Ireland politics blocked in a wrangle over whether London or Belfast should be in charge of policing and justice.
Sinn Féin has said nothing in public, but behind the scenes there is growing concern their actions will collapse the Assembly.
First and Deputy First Ministers are a matched pair and when Mr Robinson goes before the Assembly for the senior job Martin McGuinness should be re-nominated to work with him in the deputy post which he has held for a year.
If he is not nominated by the republicans Northern Ireland Secretary Shaun Woodward has few options — in theory he dissolves the Assembly and calls new elections within weeks.
In practice he could hold off through the summer marching season in the hope sense prevails.
The dispute boils down to the Sinn Féin demand that responsibility for policing and the justice system be transferred to the Stormont Executive — as they and the British and Irish Governments want, and should have happened by last month.
The DUP has dragged its heels saying it wants further guarantees over Sinn Féin's commitment to non-violence, including disbandment of the IRA's ruling army council.
Mr Robinson said if Sinn Féin put their foot down fresh elections could be called within a week.
"I believe we are in a strong position, there is nothing out there that I fear.
"Nobody has anything better to offer," he said.
While Sinn Féin has been silent on whether there is a looming crisis or not, Gerry Adams said there is a need to resolve the outstanding issue of the St Andrews Agreement, which paved the way for the devolution of power.
Talks have been taking place with the DUP, he confirmed.
In a statement Mr Adams said there were commitments in St Andrews which had to be honoured, including the transfer of policing and justice, and an Irish Language Act.
He said: "Progress has been made over the course of the past 12 months in bedding down the political institutions.
"It is Sinn Féin's intention that this work is built upon in the time ahead, including progress on the outstanding issues.
"We continue to be involved in detailed discussions aimed at achieving this. That is our focus at this time."
Nationalist SDLP deputy leader Alasdair McDonnell said Sinn Féinwas simply talking up a crisis to cover up its negotiating mistakes at St Andrews, and its subsequent political failures.
"They built their trap themselves and they walked into it," said Dr McDonnell.
"Sinn Féin will cut a deal very soon, but let there be absolutely no doubt, it will be Peter Robinson's deal.
"It will keep Sinn Féin in power, perhaps with some personnel changes, but it will not be a good deal for nationalists."
PA