Gordon Brown flew back from Belfast today after failing to broker an agreement between Sinn Féin and the Democratic Unionists over the devolution of policing powers, following 48 hours of talks.
The prime minister and his Irish counterpart, Brian Cowen, have given the two parties until Friday to find a deal to save power-sharing or the two governments will publish their own plans.
The challenge followed Brown's most intensive involvement in Northern Ireland since he succeeded Tony Blair in June 2007, a month after the historic power-sharing agreement was struck between the DUP and Sinn Féin. Brown flew with Cowen to Belfast on Monday, postponing Tuesday's weekly cabinet meeting until tomorrow and curtailing his participation in today's summit on Yemen.
They travelled to Hillsborough Castle, Co Down, after Sinn Féin warned of a grave threat to the power-sharing executive, and barely slept as the talks continued until 4am the first night and until 5am this morning.
Brown, who enlisted the help of the US secretary of state, Hillary Clinton, said he believed the two governments had drawn up a reasonable "pathway" that should be acceptable to the parties. "We believe we have proposals that make for a reasonable settlement on all the outstanding issues." But he added: "If we judge that insubstantial progress has been made we will publish our own proposals."
The two prime ministers said they had tabled a three-point plan:
Set an early date for the devolution of policing and criminal justice powers. A cross-community vote would be held in the Northern Ireland assembly in March to appoint a justice minister. Powers would start to be transferred around the time of the likely general election on 6 May.
The relationship between the new minister and the executive would be placed on an "agreed, strong and sustainable footing". This is designed to reassure the DUP that Sinn Féin would not be able to block or direct the work of the minister; the multi-party executive has to work with the agreement of all its members.
"Enhance the existing framework" for dealing with contentious parades. The DUP wants the independent parades commission to be abolished and for a new body to be appointed by the office of the first and deputy first ministers.
British sources were hopeful. But political leaders appeared gloomy after what was described as a "tetchy" plenary session this afternoon at which Martin McGuinness, Sinn Féin's deputy first minister, voiced deep frustration at the failure to devolve policing power three years after the St Andrews' talks. These paved the way for what was known as "stage one" of devolution in May 2007 – handing over powers on health, education and the environment to Northern Ireland.
McGuinness said: "I believe we have displayed extraordinary patience and commitment over the past 18 months as we sought to persuade the DUP to be partners of progress. The decision by the DUP, at the behest of the Orange Order, to make the abolition of the Parades Commission a pre-condition for the transfer of powers on policing and justice flies in the face of all that."
Peter Robinson, the DUP leader, said his party remained committed to the devolution of policing powers. "If others choose to walk away, I believe the wrath of the community will be upon them."
The breakdown of talks came as the Tory leader, David Cameron, faced pressure over secret talks between the DUP and the Ulster Unionist party convened earlier this month by the Tories. Nationalists claimed the Tories were seeking to form a pan-Unionist front.
Sir Richard Needham, the longest serving Conservative Northern Ireland Office minister, told BBC Radio Ulster it was right to convene talks to help the peace process, but he said: "That doesn't mean we do some shady deal on how to carve up seats between the Unionists against the nationalist community."
Two Catholics intending to stand for the Tories as part of a new alliance with the UUP, said they had resigned, partly in protest at the DUP talks. Peter McCann, who had hoped to stand in South Belfast, told the BBC: "Our sister party [the UUP] seemed to be intrigued into a possible link-up with the DUP. [That] was the point where I decided the … process was not going where we wanted." His remarks were endorsed by Sheila Davidson, who had hoped to stand in Lagan Valley.