Tony Blair believes there are no issues of principle remaining in the way of a powersharing settlement in the North, and that "sequencing" is key to success in this week's negotiations in Scotland.
The British prime minister is apparently satisfied that it is now only a question of how and when the DUP agrees to form an Executive with Sinn Féin and, likewise, "how and when" Sinn Féin accepts the Police Service of Northern Ireland.
This was made clear yesterday as the prime minister's official spokesman said it would be "difficult to overestimate the importance" of the talks in St Andrews, starting tomorrow. "This is it," said the spokesman, hailing "an opportunity this week which may not come again in the foreseeable future".
That was dismissed by Ian Paisley jnr last night as "a little bit too optimistic". The DUP Assembly member and son of party leader the Rev Ian Paisley said there remained "a huge fundamental chasm" over republican attitudes to the police and the rule of law. "I hope Sinn Féin are ready, willing and able to cross it but we do not have all the evidence that they are," he said.
However, Mr Blair's spokesman insisted the November 24th deadline for a devolution deal held firm, adding that the prime minister and Taoiseach Bertie Ahern expect to know by the end of this week's negotiations whether or not it is possible.
"We'll tell it like it is," said the spokesman, again indicating that Mr Blair will give an early and frank assessment of the situation if he leaves St Andrews convinced the parties are not ready to deal.
Downing Street's view is that the Sinn Féin leadership is "in a much better position" to resolve the policing issue than at any time before.
At his regular Monday briefing the spokesman told journalists: "I think it is difficult to overestimate the importance of this week. This is it.
"Last week, we said that the IMC [Independent Monitoring Commission] report on the IRA's inactivity laid the basis for a final settlement.
"We are not taking anything for granted and there are issues which could trip us up, but the fundamentals are clear."
The spokesman continued: "Unionism accepts that at some stage it will have to share power with Sinn Féin. The question is how and when, not if.
"Equally, Sinn Féin, according to the IMC report, accepts that it had to engage with the police. The question is how and when, not if. The issues are about sequencing, not fundamental principle."
However, DUP deputy leader Peter Robinson has confidently predicted that the St Andrews talks will not be "the end of anything".