The future of Northern Ireland's power-sharing government could hinge on a meeting today of Sinn Fein leaders who accuse unionists of blocking a deal on the devolution of policing and justice powers.
Sinn Fein president Gerry Adams claimed the Democratic Unionists derailed talks on the issue at the Stormont Assembly by demanding concessions on controls over Orange Order parades.
But DUP leader Peter Robinson said progress was being made in the negotiations and claimed republicans were creating an unnecessary political crisis.
The Sinn Fein ard chomhairle was meeting in Dublin this morning, with the party's ruling executive expected to announce their next move within hours.
There are fears that republicans will crank-up political pressure and may go as far as pulling out of the power-sharing government.
Three years ago Sinn Fein backed the new policing arrangements in Northern Ireland on condition that the Assembly eventually took over political responsibility for law and order from Westminster.
But with unionists insisting that the conditions must be right before completing the transfer of the powers, and with Sinn Fein demanding they close a deal, the long-running dispute has now reached crisis point.
There is mounting speculation that the British and Irish governments will be forced to step in to salvage the process, with it now appearing increasingly likely that Prime Minister Gordon Brown and his opposite number in Dublin, taoiseach Brian Cowen, will have to become directly involved.
The last two days have seen an escalating war of words between the DUP and Sinn Fein.
But after republicans announced yesterday that talks at Stormont had ended without agreement, Mr Robinson called for calm.
"It seems every time I think there is a good day (in the talks), I awaken to find someone is moving away and moving backwards," he said.
"People recognise that the community in Northern Ireland doesn't want to go back to the old days, they want a steady hand on the helm and want to see progress being made."
Sinn Fein wants to secure a date for the transfer of the powers while the DUP has been pressing for changes to how controversial loyal order parades are governed.
Currently the Parades Commission adjudicates on processions like Drumcree in Portadown, Co Armagh, where Orangemen have been barred from walking along the nationalist Garvaghy Road.
Mr Robinson said both sides in the Stormont talks had recognised there was a need for engagement on parades.
"I thought we were moving in the right direction and were starting to see the areas of concern to the Ulster Unionist Party (UUP) and to Sinn Fein in relation to the structures recommended by the Ashdown Review. We were looking at other ways," he said.
In the summer of 2008 Paddy Ashdown's Strategic Review of Parading came back with what it described as interim proposals placing local dialogue at the heart of the process.
It said that, where possible, the dispute would be solved in the first instance by dialogue between those organising the parade and those objecting - local councils would facilitate such talks, if necessary.
If such dialogue failed, the highest office in the Northern Ireland Executive, the Office of the First and Deputy First Minister (OFMDFM) would appoint a mediator, drawn from a list selected by public appointment.
Nationalists have warned against repoliticising adjudication on parades.
Mr Adams said the talks effectively ended on Wednesday night and he accused the Democratic Unionists of "playing the orange card" by demanding concessions on loyal order parades.
He said the partition of Ireland "gave unionists a little orange state", and claimed organisations such as the Orange Order had since played a key political role.
"Even today most unionist politicians are in one or other of the loyal orders and those that aren't listen attentively to what the Orange wants," he wrote in his blog, Leargas.
"And what is that in 2010? They want the scrapping of the Parades Commission and progress on the ground - in other words marches through Catholic areas.
"It's sad that, even now, sectarianism and triumphalism still has such a huge grip on a large section of the unionist psyche.
"The orange card, played so often in the past to get their own way, is being played again as the DUP try to get the Orange Order what the Orange Order wants."
He added: "Sorry folks - it doesn't work like that any more. Those days are gone. The orange state is gone."
The Ulster Unionists and the nationalist SDLP, which also holds seats on the Northern Ireland Executive, dominated by the larger DUP and Sinn Fein, expressed concerns at the escalating dispute.
Their fears were echoed by the Alliance Party, tipped to be a compromise candidate to take on a new Justice Ministry at Stormont if the row can be resolved and the policing powers devolved.