The Ulster Unionist leader, Mr David Trimble, meets Mr Tony Blair in Downing Street today following further sharp exchanges between unionists and republicans on the causes of the current crisis.
There are fears that time is short to restore the political process and it is thought the British Prime Minister has just weeks to devote to Northern Ireland before any possible war with Iraq.
However, Downing Street made it clear yesterday that Mr Blair would give as much time as possible in the coming weeks to restoring the political process. It is expected that IRA activity, demilitarisation and policing legislation, currently before the House of Lords, will be prominent issues in the coming weeks.
The UUP said that its participation in talks on restoring the Stormont institutions depended on Mr Blair's handling of republicans.
Mr Trimble walked out of a session of multi-party talks at Stormont co-hosted by the Northern Secretary, Mr Paul Murphy, and the Minister for Foreign Affairs, Mr Cowen, just before Christmas. He cited evidence of IRA activity referred to in an Irish Government briefing paper which was accidentally leaked during talks with the British government at Farmleigh.
Mr Michael McGimpsey, a former Stormont minister, said yesterday his party wanted to hear from the Prime Minister on what republicans must do to revive the peace process. "The British and Irish governments and other partners to \ agreement have let us down in recent months over the issue of Sinn Féin's exclusion from the Executive," he said.
"What we now want to hear from the Prime Minister is what he believes the republican movement must do to put the process back on its feet."
Mr Blair is expected to meet the SDLP on Thursday and Sinn Féin tomorrow. However, with the gulf between republicans and unionists remaining wide, Sinn Féin's Mr Gerry Kelly yesterday dismissed calls for his party to be excluded from any restored institutions at Stormont. "The unionists decided to pull down institutions which were driving the whole process forward," he said.
"The wrong way to argue to get the institutions up and running again is to say that Sinn Fein must be excluded. Remember, when you are talking about excluding Sinn Féin, you are talking about excluding the largest nationalist party and the largest nationalist vote in the North of Ireland.
Mr McGimpsey accused Mr Kelly of "breathtaking arrogance". "We are in this mess because of the actions of republicans," he said.
The SDLP leader, Mr Mark Durkan, accused the Ulster Unionists and Sinn Féin of making "the same old arguments".He also criticised Ulster Unionist MP, Mr Jeffrey Donaldson, for insisting that unionists had lost confidence in the peace process.