Sinn Fein leader Gerry Adams has criticised the decision by Ulster Unionist MPs that they could no longer support the Northern institutions.
In Dublin for talks with Taoiseach Bertie Ahern, Mr Adams said: "It confirms for many people that Jeffrey Donaldson and David Burnside were not ever really for the Good Friday agreement.
"Indeed, Jeffrey has made a bit of a career of walking out of negotiations. I think if they were serious even from a unionist perspective - on all these outstanding issues, if they were serious about genuinely building a peace process, they should stick to the process, argue their corner and work with the rest of us to make this work."
Mr Adams went into his discussions with Mr Ahern, accompanied by senior party colleague and Northern Ireland Education Minister Martin McGuinness, with uncertainty still hovering over the timing of the Irish and British Governments’ new joint document on the peace process.
The Sinn Fein leader said: "The last time we had sight of the propositions the two Governments had in mind was at the beginning of the Weston Park talks, and they were short of the Good Friday agreement at that point.
"There was a positive sign at the end of the Weston Park talks when the Government spokesmen committed themselves to a package of propositions bedded in the Good Friday agreement and aimed at implementing it.
"That’s the only way to go. If there are difficulties, they will have to be overcome and we want to see both the package produced and publicised as quickly as possible.
"The Good Friday agreement is the people’s agreement and everyone needs to have a share of it and a sense of what is going on.
"And our only condition is that it is about a strategic plan, a strategic bridge to deliver all of the outstanding elements of the agreement."