The Government has been challenged to immediately stop consideration of five active cases involving on-the-run IRA terror suspects who have asked for assurances they are not wanted by police.
A Stormont minister issued the demand during a fiery emergency meeting of the devolved legislature in Belfast, called to debate the continuing controversy over a deal the last Labour government struck with Sinn Fein that saw more than 180 individuals issued with letters making clear they could return to the UK because the authorities were not seeking them.
While the majority of the cases were dealt with under the last government, almost 40 outstanding applications were taken on by the coalition Government when it assumed power in 2010.
Today it emerged that five cases apparently remain outstanding, with the Northern Ireland Office (NIO) understood to be still deliberating on whether those applicants should receive a letter.
Addressing a packed chamber at the conclusion of an ill-tempered and rancorous debate at Parliament Buildings, Democratic Unionist Economy Minister Arlene Foster first directed a pointed message to Sinn Fein.
"They have always had a cavalier attitude to the rule of law but they need not underestimate our continuing determination to rebuild confidence and that must start, I have to say Mr Speaker, with the five cases we have learnt of this morning."
Mrs Foster then delivered a stark ultimatum to the NIO regarding the cases.
"They must immediately go, they have to be stopped immediately - I think that will be a mark of how this issue goes forward and we will be asking that question of the Secretary of State (Theresa Villiers) very, very quickly.
"I make it very clear from this House that we are not just dealing with the past, as we have learnt this morning, we are also dealing with the here and now in relation to this system."
Asked about the five cases, the NIO said it would not be commenting in detail on the OTRs scheme due to the forthcoming judge-led review of the system, which was announced by Prime Minister David Cameron yesterday.
A spokeswoman for the NIO said: "The review will produce a full public account of the operation and extent of the OTRs scheme. It is important now that we let this inquiry run its course."
The five cases were brought to light by Stormont Justice Minister who said he had been informed of their existence by a "senior NIO official" this morning.
Details of 180-plus letters sent to 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 light on the wider policy of sending such letters to on-the-runs, with many politicians in Northern Ireland reacting with fury, claiming the scheme was operating without their knowledge.
There is a degree of confusion as to when the five cases came to the attention of the NIO. Mr Ford said it was his understanding from his discussion with the NIO official that they came to light in "late 2012", but that runs contrary to the NIO's official position that the only cases it has dealt with were lodged prior to the 2010 general election.
The Assembly was recalled for the additional sitting following a request by DUP First Minister Peter Robinson at the height of this week's political crisis over the scheme.
When Mr Robinson made the announcement on Wednesday, shortly after he had threatened to resign over the issue, there were fears the future of the power-sharing executive would be on the line during today's plenary session.
Those concerns receded last night when he withdrew his ultimatum in response to Mr Cameron's announcement on the review.
However, the two hour debate was still extremely fractious, with Speaker Willie Hay forced to call for order on numerous occasions as members exchanged brickbats across the chamber.
The DUP claimed assurances it has received from the Government yesterday about the status of the letters already issued had rendered them effectively "worthless".
But Sinn Fein has rejected that analysis, with the party's Deputy First Minister Martin McGuinness insisting "nothing could be further from the truth".
Mr McGuinness has claimed the letters were nothing more than official confirmation from the authorities that there was no evidence linking individuals to offences, and not in any way an amnesty. He claims the fact other republicans were denied letters - and told they would be arrested if they entered the UK - proves his point.
The Sinn Fein veteran today insisted rival politicians at Stormont have been aware of the OTR scheme for a long time - noting references to it in a number of public forums, reports and publications in recent years - and further claimed the angry reaction to the issue this week had been "contrived" to deflect the public away from that fact.
During the debate, in which a DUP motion condemning the scheme expectedly passed with only Sinn Fein opposition, Mr McGuinness accused unionists of irresponsibly threatening the stability of power-sharing.
He claimed the DUP and the Ulster Unionist Party (UUP) were in the thrall of loyalist extremists and insisted the recall of the Assembly was more about political posturing ahead of forthcoming elections.
"I am frustrated that the stability of these institutions have been irresponsibly threatened this week and a sense of crisis has replaced the much-needed focus that we needed to get agreement on issues relating to the past," he said.
"I am frustrated that those historically opposed to the peace process and to power-sharing are being allowed to chip away at the process by using legacy issues as a vehicle to pursue their negative and rejectionist agenda."
He added: "I am frustrated that those extreme loyalists shape the behaviour of the two main unionist parties."
Mr McGuinness continued "I am frustrated we are here today discussing a motion which is as irresponsible as the threat to collapse this Assembly.
"Today's recall and motion is about the upcoming election and about the political posturing within unionism. Frankly, I believe the people out there deserve better."
The Deputy First Minister said the peace process had been built by politicians showing leadership.
"At many times throughout this process I could have walked away, I could have threatened to resign. I have not done that," he said.
"I have sought solutions and agreement and we have progressed to where we are today because of those agreements. The peace and political process needs (to be) defended, protected and promoted by all political leaders - it certainly does not need to be threatened."
At the outset of the plenary exchanges, Mr Robinson accused former prime minister Tony Blair of a "deliberate deception by omission" by failing to tell the majority of politicians in Northern Ireland about the agreement his government struck with Sinn Fein.
The DUP leader said his predecessor Ian Paisley had written to Mr Blair when he was in power asking for assurances that no concessions had been given to Sinn Fein about on-the-runs.
He said the reply stated there were no plans to legislate on the issue, and no amnesty had been offered but, Mr Robinson said, it did not make mention of the administrative scheme to send OTRs assurance letters.
"The answer that there were no plans to legislate and no amnesty would be introduced was a deliberate deception, a deception by omission, for the Government could easily at that stage have indicated that there was an administrative process which included giving letters to OTRs under way," he told MLAs
Opening the Assembly debate, Mr Robinson said: "The outcome of the Downey case was morally outrageous and an affront to justice, but more than that it exposed to the full glare of public attention a scheme that had been agreed well over a decade ago by Sinn Fein and the UK Government.
"It was followed by outrage, that outrage, I have to say, was not manufactured or synthetic, it was real, it was an outrage felt by victims, it was an outrage felt by those within the political process that they had been by-passed by the British Government and by Sinn Fein."
Social Democratic and Labour Party (SDLP) leader Dr Alasdair McDonnell said people had the right to know if any other secret deals had been struck.
"It's impossible to have a proper informed debate on issues that haven't been fully disclosed - we must know, we must get all the information, we must achieve honesty, openness and transparency around all these issues, starting with rejecting any possibility of secret deals going forward," he said.
He accused the Labour administration and former Northern Ireland secretary Peter Hain of cynicism.
"The cynicism we were up against was Peter Hain and the British government working with Sinn Fein to demonstrate contempt for our parliamentary democracy and antipathy and disdain for victims.
"The structures of government must be and must feel to be fully accountable to our people - power must fundamentally lie with the people on the street, the citizens. This is far from the place we find ourselves in today. As my colleague Mark Durkan (Foyle MP) said yesterday, we didn't work so hard to end the dirty war just to end up with a dirty peace."
Ulster Unionist leader Mike Nesbitt branded the scheme "perverse" as he paraphrased a famous Orwellian line.
"All citizens are subject to the law, but some citizens are less subject than others," he told MLAs.
"George Orwell coined the original phrase as a warning - 'Don't go there', he said. We have gone there.
"You expected a loved one to phone the police and say 'do you have any evidence about who committed the murder?'. You do not expect the murderer to be able to phone the police and say 'do you have any leads that would end up with me going to prison?'.
"It is a perversion of justice."
The crisis at Stormont erupted as party leaders were attempting to find a way forward on stalled proposals for dealing with outstanding peace process issues, including the toxic legacy of the past, drawn up by former US diplomat Dr Richard Haass.
Mr Nesbitt said the actions of Sinn Fein over the OTR issue had effectively doomed that process.
"Let me make clear, for the Ulster Unionist Party not only is Haass over but the party leaders (meetings to discuss Haass) is over - and it is over because of Sinn Fein and bad faith."
Mr Ford, speaking in his capacity as leader of the cross-community Alliance Party, said many questions remained to be answered about the "misguided and secretive" scheme.
But he said politicians in Northern Ireland still had to face up to dealing with the legacy of the past, whatever the outcome of the judge-led review.
"Whatever emerges from the inquiry, there is a moral obligation to deliver for victims and survivors," he said.
"Whatever differences we have about what has happened, we must work together to build a shared future for everyone.
"Parties must not use these revelations as an excuse for not dealing with the outstanding issues of flags, parades and the past. The task may now be more difficult than ever, but it is also more important than ever."
There were also angry scenes outside the Assembly chamber when victims of IRA terror, including the 1987 Remembrance Day bomb in Enniskillen, attempted to confront Sinn Fein MLAs, among them Mr McGuinness, in the Great Hall of Parliament Buildings.
Earlier in the Great Hall, Mr McGuinness had pointed out his party was not the only one who forwarded names to the British authorities seeking clarification on the status of individuals.
He said the Irish Government had also presented names to the UK Government.
"The other point to be made, which is probably something that is not in the public domain, I think the media should ask some questions about was Sinn Fein the only party to put forward the names of people who approached us who thought that they were being sought by the authorities, because I have received information that the Irish Government actually put forward names in the context of the same scheme," he said.
"So we weren't on our own in this and I think that adds absolutely to our contention that this process began in a very serious way in the aftermath of what happened at Weston Park (peace process talks in 2001)."
According to the judgement in the Downey case, an NIO briefing note from September 2002 recorded 162 names provided by Sinn Fein - 61 of whom were told they could return.
The NIO said the Irish Government sought information on two people and the Prison Service information on 10.
Ireland's Department of Justice tonight made clear the authorities in Dublin did not issue letters.
"We had no equivalent to the administrative scheme put in place by the NIO and, accordingly, did not issue letters of the kind in question in the John Downey case," said a spokesman.