British prime minister Tony Blair has attached considerable significance to a statement from DUP leader, the Rev Ian Paisley, responding to a British government warning that if devolution is not restored by March 26th then Stormont will shut down "indefinitely".
Dr Paisley said last night: "If a government cannot be formed on March 26th because Sinn Féin fails to deliver it will be clear that Sinn Féin alone is to blame."
While ostensibly negative, London sources said it was also implicit in this response that if Sinn Féin delivers on policing then a restored Northern executive can be formed by the St Andrews Agreement deadline of March 26th.
The sources acknowledged that such methods of interpretation are tortuous and beyond the interest of most people but that nonetheless the "converse of Dr Paisley's response must be true, which is that he would share power if Sinn Féin delivers on policing".
Mr Blair also saw considerable merit in Dr Paisley's words.
His chief spokesman told The Irish Times last night: "Dr Paisley's comments, taken alongside the outcome of the Sinn Féin ardchomhairle at the weekend, confirm the prime minister in his view that it is possible to arrive at a situation where there will be full support for the police and a powersharing executive by March 26th."
"This is the way the DUP does business - negatively," added a senior talks source last night.
"Dr Paisley seems to be responding to the likes of Jim Allister (DUP MEP) who say that it would take way beyond March 26th to test whether Sinn Féin had properly endorsed the PSNI. He is saying it can be done by March 26th and that's significant," he added.
Sinn Féin's initial response was unenthusiastic. "How in print do you describe a long yawn," said a senior party source last night.
Earlier yesterday Dr Paisley issued a highly guarded positive response to the weekend decision by Sinn Féin to hold an ardfheis on policing on Sunday week.
"The Sinn Féin decision to call their special conference to take a decision on policing is a step forward.
"However it only amounts to movement when there is full delivery on the ground," he said.
He also referred to how the motion that will be put to the ardfheis appeared to promise Sinn Féin support for the PSNI only after the DUP had made a commitment to powersharing and indicated it would accept the transfer of policing powers to the Northern Executive by May 2008.
Or failing such DUP commitments, support for policing would appear only to come into effect after the British and Irish governments dissolved Stormont and implemented Plan B, the strengthening of "partnership arrangements" in how the North was run.
"Any analysis of the motion passed on Saturday allows for several different, if not contradictory, interpretations," said Dr Paisley, referring to this point.
"The question is do they intend to proceed with offering support to the police and the courts and encouraging their supporters to do so as soon as the motion is passed. The DUP will not be moving until there is full delivery on the ground and the DUP will not be found wanting if there is," added Dr Paisley.
The Sinn Féin source, referring to the two statements from Dr Paisley yesterday, said the overall Sinn Féin response could be encapsulated in what the party's chief negotiator, Martin McGuinness, told reporters at Stormont yesterday.
Mr McGuinness said: "The question has been asked, if the (ardfheis) motion is passed what does this mean? It means it's over to you, Ian."
Sinn Féin is expected to begin a series of public meetings on policing ahead of the ardfheis starting this coming weekend, with party president Gerry Adams and also Mr McGuinness taking the lead in arguing the case for endorsing the PSNI.