Ulster Unionists have accused Sinn Féin leader Gerry Adams of being "a deal breaker" in terms of the Good Friday Agreement after his call for a "plan B" to be prepared.
Mr Adams, in a recent interview with the Irish News, said that if unionists continued to refuse to work the dev-olved institutions, the British and Irish governments needed to produce an all-Ireland transitional mechanism.
Yesterday (Tuesday) Michael McGimpsey of the UUP said Mr Adams was trying to pass the blame for the political difficulties.
"This is a vintage Gerry Adams performance," he said.
"The Sinn Féin president wants to pass the buck and absolve himself and his party of any responsibility for the current crisis by pointing the finger at unionists. Nice try.
"One would think from reading Mr Adams's comments that it was, in fact, unionists who had been importing arms, spying on others and who had a private army that is responsible for bringing down the institutions on three different occasions.
"The Provisional movement, which is standing in the dock, having destroyed the trust of others, is in no position to lecture unionists on what we should be doing."
According to Mr McGimpsey, it is "Mr Adams and the party he represents that are clearly deal breakers".
Mr McGimpsey said Sinn Féin, in trying to push for a plan B, was clearly stating that it could not honour what it had signed up to.
"If they can't deliver, if they can't make the final hurdle, then they need to let all the parties who are keen to see the agreement implemented know ab-out it. The agreement is the only show in town," he said.
Meanwhile, Mr Adams has said there is little sign that unionism is contemplating a more positive approach to the agreement or that those who would advocate such an approach are in a position to deliver.
Speaking in Boston to the Irish American Partnership, he asked: "If this is the case does this mean the process is over?"
Mr Adams said this was essentially a question the unionists and the British government had to answer.
"The British government has pandered to unionism – there can be no doubt about that – but the cancellation of the elections was motivated also by London's agenda," he said.
"There can be no confidence that the political process will survive unless Mr Blair commits to a certain date for the election as soon as possible and without any preconditions or qualifications.
"This is a matter of political principle. It is the democratic imperative. It is also the right tactical and strategic thing for Mr Blair to do.
"An election is also required to set a new context and to reinvigorate the process," he added.
Mr Adams repeated his analysis that "the two governments need to make it clear that for unionism the Good Friday Agreement is as good as it gets".
He argued that if there could not, at this time, be political institutions of the kind envisaged by the agreement, then the two governments must proceed along an all-Ireland path to implement all other elements and within a democratic mechanism in which London and Dublin are both held accountable.
"Such an arrangement needs to be put in place until the unionists are prepared to engage properly and on the basis of equality," Mr Adams said.
DUP deputy leader Peter Robinson has said that unless nationalists and republicans face up to political realities, Northern Ireland may be set for a lengthy period of direct rule.
Mr Robinson said that sooner or later the penny would drop with nationalists that the Belfast Agreement could not provide the way forward.
The alternative, he said, was not to go back to the old days but to move forward to a future on which unionists and nationalists could agree.
Mr Robinson said that both SDLP leader Mark Durkan and Mr Adams parroted the contention that there would be no renegotiation of the agreement and that this was the only acceptable way forward.
"If nationalists, for 30 years, would not accept an agreement which did not command the support of the minority community, then how can they justify continuing with an agreement which does not command the support of unionism?" Mr Robinson asked.
Unless any agreement had the support of unionists and nationalists, it would not survive, he said.
"The choice for nationalists is not between the Belfast Agreement and some all-Ireland arrangements – it is between a new settlement which unionists and nationalists can agree and direct rule from Westminster, which largely excludes all the people of Northern Ireland," Mr Robinson said.
He also said Sinn Féin's links with the IRA would increasingly be a factor that the party would need to address.
"If the IRA's continuing role and activity excludes Sinn Féin from responsibility (in government) both here and in the Republic, it will soon be seen it is in their interest to close down the terror machine," Mr Robinson said.
With the UUP fading from its central position within unionism, republicans had lost their golden goose, he said.
"Things will never be the same again. The DUP will not roll over the way the UUP did but equally will stick to any deal that it does," Mr Robinson said.
"The nationalist community had better start the learning process – that no 'proposal' for Northern Ireland will endure without the support of the DUP.
"The opportunity for a settlement in Northern Ireland does exist but is being delayed by the nationalist refusal to get real and by irreconcilable divisions in the UUP."
Last night SDLP leader Mark Durkan said it was not nationalists but the DUP that was out of touch.
It was the SDLP which had put inclusion into the agreement, he said.
"It includes those who have voted yes and those who have voted no. It includes the DUP in government every bit as much as any other party," Mr Durkan said.
"It is not, as Peter Robinson claims, that the agreement has failed. Rather it is that parties have failed the agreement. Unionists are not against the agreement, as much as they are dis-appointed with the failure to deliver the end to paramilitary activity that it promised.
"The truth is that continued IRA activity has turned pro-agreement unionists off and given a penalty kick to the wreckers in the DUP."
Mr Durkan said that was why Sinn Féin should be doing more to play its part in ending paramilitarism instead of talking of a 'plan B'.
