Northern Ireland's First Minister, Peter Robinson, threatened to resign yesterday unless there is a judicial review of the collapse of the trial of a man suspected of carrying out a 1982 IRA bombing in London.
Robinson said the British government had kept him in the dark on the issue of secret amnesty letters given to fugitive suspects - the issue that caused the high-profile Hyde Park bombing trial to be aborted.
A judge on Tuesday ruled that John Downey, 62, should not be prosecuted for the attack after it emerged he had received an official letter in 2007 assuring him he would not face prosecution if he re-entered the United Kingdom.
The letters were part of the 1998 Good Friday agreement that ended decades of sectarian violence in Northern Ireland.
Downey was charged with killing four cavalry soldiers in the Hyde Park bombing by the Irish Republican Army.
He was arrested last May at London Gatwick Airport while en route to Greece.
A visibly furious Robinson, who has headed Northern Ireland's devolved administration since 2008, said he was "incandescent with rage" that he did not know about the letters.
"I am not prepared to be the first minister of a government that is kept in the dark" by London on matters relating to Northern Ireland, he said.
"I want a full judicial inquiry into all of these matters so that we can see who knew, when they knew, what they knew. I want all of the letters rescinded."
British Prime Minister David Cameron has condemned the actions that led to the collapse of the case against Downey as a "dreadful mistake".
He told the Commons the letter giving Downey a false assurance he was not wanted by British police over the IRA attack should never have been sent and a rapid factual review would be carried out to make sure "this cannot happen again".
"But whatever happens we have to stick to the principle that we are a country and a government under the rule of law," Cameron said.
He said it was "absolutely shocking" that Downey was not going to be tried for the bombing.
The government's chief legal adviser, Dominic Grieve, England's attorney general, told Parliament Downey should never have received the letter.
Families of the victims of the bloody 1982 attack said they felt "devastatingly let down".
Such letters of assurance have been sent out to 187 so-called "on-the-runs" living outside British jurisdictions, who sought clarification on their status following the 1998 Northern Irish peace accords between its broadly Protestant British and Catholic Irish communities.
Additional reporting by The Guardian