Prime Minister Gordon Brown may be forced to make a fresh intervention later today unless the Democratic Unionist Party and Sinn Fein can hammer out an 11th hour deal on the transfer of policing and justice powers to the Northern Ireland Assembly.
Peter Robinson and Martin McGuinness have until lunchtime to come up with an agreement, otherwise the British and Irish Governments will published their own proposals.
Mr Brown and the Republic's Taoiseach, Brian Cowen, who have already been to Hillsborough Castle to try to broker a settlement, want the two sides to agree a process to transfer the powers from London to Belfast by the start of May.
The key sticking point is DUP demands for the abolition of the Parades Commission, which adjudicates on contentious marches, and instead leave it to an independent panel, appointed by the office of the First and Deputy First Minister, to arbitrate.
But they have also insisted they are also open to alternative proposals on parades.
New disclosures of more secret talks between Mr Robinson's DUP and Sir Reg Empey's Ulster Unionist Party in an attempt to agree a unionist unity electoral pact are unlikely to help the already tense atmosphere around the negotiating table, and the signs going into today's discussions offered little hope of a breakthrough.
The parades issue clearly remains the major obstacle and if there no deal, then there is a distinct possibility Sinn Fein will walk away, collapsing the powersharing executive and triggering new Stormont elections.
Sinn Fein president Gerry Adams said: "Anybody who thinks that the price of policing and justice is a walk down the Garvaghy Road (Drumcree) or through Ardoyne (north Belfast), it is just ridiculous. Let's deal with the issues sensibly, let's do our best to make sure the outstanding matters of this agreement are implemented."
The DUP's Sammy Wilson, the Stormont finance minister, said his party was in the "mindset" to do a deal and was capable of making a sustainable agreement which members could stand by.
He added: "I would rather have a 'Made in Ulster' deal than something which is brought here and imposed on us, whether a suggestion or a proposal from London or Dublin.
"A 'Made in Ulster' deal will stick, a proposal from London or Dublin will mean that in some way we are seen as incapable of dealing with these things."