A political crisis in Northern Ireland over the Government's handling of on-the-run republican terror suspects receded tonight when the announcement of a judge-led review prompted Stormont's First Minister to lift his resignation threat.
Peter Robinson stepped back from the brink after Prime Minister David Cameron commissioned the probe into a scheme that saw letters sent to more than 180 individuals advising them they could return to Northern Ireland without fear of prosecution.
The Democratic Unionist leader, whose resignation would have seen the institutions fold, and likely a snap Assembly election, claimed assurances he had received from the Government about the letters had now rendered them effectively "worthless".
Mr Robinson had earlier said the Government needed to rescind the letters to prevent him walking away from the Executive.
Sinn Fein, the other main partner in the mandatory five party coalition, had accused the DUP and other unionists of "grandstanding" on the issue and claimed the threat of collapsing the Executive was a ruse to distract the public from the fact they already knew about the process to deal with the on-the-runs (OTRs).
Mr Robinson said the deluge of calls his party had received from victims and other members of the public demonstrated there was nothing "synthetic" about the crisis.
The DUP leader said he welcomed the review and said he now had no need to tender his resignation.
"I do not intend to resign, on the basis that if you get what you want why on earth would you want to resign," he said.
Last night he requested the Assembly to be recalled and, if the Government's response today had not been what he desired, it was likely he would have resigned at some point before, during or after that special sitting of the House tomorrow.
The plenary session will go ahead tomorrow but some of the tension around it now appears to have been defused.
As well as commissioning the review, the Government said it would be making clear to all those who had received a letter in the past, as part of a deal Sinn Fein struck with the previous Labour administration, that if evidence now existed, or emerged in the future, which linked them to an offence, they could be questioned or prosecuted.
Mr Robinson claimed that move represented a fundamental change to how the scheme had operated before.
"I think that makes it clear that they have a fairly worthless piece of paper," he said.
The DUP leader added: "I think there will be a lot of on-the-runs who will sleep less easy tonight."
Details of 187 letters sent to so-called on-the-run republicans (OTRs) emerged when the case against a man charged with the 1982 IRA Hyde Park bombing collapsed.
John Downey, 62, from Donegal, denied murdering four soldiers in the attack in London.
The case against him was ended because Government officials mistakenly sent him one of the assurance letters in 2007 telling him he was no longer a wanted man.
But the collapse shone the light on the wider policy of sending such letters to on-the-runs, with unionist politicians in Northern Ireland reacting with fury, claiming the scheme was operating without their knowledge.
Announcing the review this afternoon, the Prime Minister said he accepted calls for a "full, independent examination" of the process.
"I agree with the First Minister of Northern Ireland that, after the terrible error in the Downey case, it is right to get to the bottom of what happened," Mr Cameron said.
"The case has already been referred to the Police Ombudsman but, as the First Minister has said, we should have a full, independent examination of the whole operation of this scheme."
The judge will be given "full access to government files and officials" and will report by the end of May, Mr Cameron said, with the findings being published.
Sinn Fein has insisted that those republicans who received letters only obtained them because the police were not seeking them in connection with offences - and therefore the documents did not amount to any form of amnesty.
Earlier, Sinn Fein Deputy First Minister Martin McGuinness said a number of other republicans who had applied were denied letters and told they would be arrested if they entered the UK.
"So that information blows out of the water this argument of amnesty or immunity or get-out-of-jail card," he said.
Tonight Sinn Fein Assembly Member Alex Maskey described the review announced by Mr Cameron as "unnecessary".
"This announcement is a political fig leaf for the DUP to try and get them off the hook they jumped on to over the past few days," he said.
Sinn Fein questioned DUP claims that it was unaware of the deal, noting that senior Police Service of Northern Ireland (PSNI) officers had previously briefed members of the PSNI's scrutiny body - the NI Policing Board - on elements of the scheme, albeit without mention of the letters.
DUP members were present at the Policing Board meetings. The issue was also mentioned in the high-profile 2009 Eames-Bradley report on dealing with the legacy of the Troubles and in a book by Tony Blair's former chief of staff Jonathan Powell.
Mr McGuinness said: "I think that the angst among unionist politicians is more centred around the common belief out there in society and in the media that they knew all about this.
"They may not have known about the letters, but they knew about the scheme and they knew that these people who were described as on-the-runs were being processed."
Mr Robinson said he did not regret threatening to resign.
"There does come a time in the life of any politician where they have to determine whether it is more important to stay in a job or to make a particular point that is relevant to those that they represent," the East Belfast MLA said outside Stormont Castle tonight.
"That's what I have done."
Subsequent to Mr Cameron's announcement but prior to Mr Robinson's public response, Northern Ireland Secretary Theresa Villiers issued a statement of further detail on the Government's attitude toward the OTR scheme.
She insisted nothing had ever been issued that amounted to an amnesty.
"That remains the case," she said.
"No recipient of such a letter should be in any doubt that if evidence emerges in the future in connection with terrorist offences committed before the Belfast Agreement they will be liable for arrest and prosecution."
In claiming the letters were now meaningless, Mr Robinson pointed to the conclusion of Ms Villiers' statement.
She said: "We will take whatever steps that are necessary to make clear, to all recipients of letters arising from the administrative scheme, in a manner that will satisfy the Courts and public, that any letters issued cannot be relied upon to avoid questioning or prosecution for offences where information or evidence is now or later becomes available."
Tonight the Irish government reacted to recent developments north of the border.
Deputy prime minister Tanaiste Eamon Gilmore welcomed the review.
He said the issues raised this week underlined the need for "comprehensive and effective arrangements" for dealing with the legacy of the past and for addressing the needs of victims.
"We can never forget the terrible events that occurred during the Troubles and we must pay heed to the ongoing suffering of surviving victims of the Troubles in Ireland and in Britain, some of whom will not and should not be expected to forgive," he said.
"Nevertheless, we cannot allow the past to destroy the peace and stability of the present and the prospect of a better future for generations to come. That is the most immediate and pressing challenge for the political leadership in Northern Ireland."