A fresh inquiry into the events of Bloody Sunday in Derry 26 years ago will be announced by the British Prime Minister, Mr Tony Blair, in a statement to MPs in the House of Commons this afternoon.
The inquiry is expected to be headed by a senior Law Lord sitting with two other judges, one of them from a Commonwealth country. Contrary to speculation in London, it is understood the three-member team will not include an American judge.
It is believed that no decision has been taken on the question of an apology for Bloody Sunday and that Mr Blair has decreed that an apology must depend on the inquiry's conclusions.
The long-awaited statement will come at 3.30 p.m., just hours before the 26th anniversary of the fateful day in Derry when 14 unarmed civilians were killed by members of the Parachute Regiment in highly controversial and still-disputed circumstances.
Downing Street and the Northern Ireland Office were still officially refusing to confirm the fact of Mr Blair's intended statement last night, even after his intentions had been indicated to the Taoiseach's office and to the relatives of those who died.
And while the precise details of the inquiry - its personnel, terms of reference and legal status - remained a closely guarded Whitehall secret there were strong indications that it would satisfy Mr Ahern's repeated demand that it be comprehensive and independent.
The decision follows lengthy British consideration of the assessment of the evidence about Bloody Sunday compiled by the last Irish administration, and protracted and often fractious discussions involving the Northern Ireland Office, the Ministry of Defence and Downing Street.
Regarded as a crucial test of the Blair government's commitment to justice and fairness, the decision will be an important boost for the SDLP leader and Foyle MP, Mr John Hume. Believed to have been urged by Dr Mo Mowlam, the Northern Ireland Secretary, in the face of stiff resistance from the defence establishment, the new inquiry also represents a calculated political risk for Mr Blair's government in terms of unionist and British public opinion.
The Conservative Party is expected to oppose the new investigation. In an early indication of the party's mood, the shadow Northern Ireland Secretary, Mr Andrew Mackay, said an apology for Bloody Sunday would be wrong. Mr Mackay said: "We feel that Prime Minister Major was right to have said that those who died were innocent victims of the troubles. However, we think that an apology would be quite wrong because that would imply someone was culpable of killing those who died. "It ill-behoves - with the benefit of hindsight 25 years on - anyone to second-guess the actions of young soldiers on the streets of Londonderry under fire."
On the other hand, senior unionist politicians were yesterday signalling a fairly relaxed attitude to the question of a possible apology. And Conservative and Unionist sensitivities may be soothed if it is confirmed, as wellplaced sources claimed last night, that the Ministry of Defence has won some important behind-the-scenes battles concerning the question of immunity for former officers and soldiers giving evidence to the new inquiry. Mr Blair's statement will be closely scrutinised to see whether the provisions of the new inquiry preclude the possible prosecution of officers or soldiers who served in Derry in 1972.
Relatives of some of those who died have said they have no interest in seeing prosecutions, and argued for an investigation which would separate the search for truth from any question of retribution.
The Ulster Unionists have said that any inquiry should be matched by an investigation into the alleged role of then senior Irish politicians in the events which saw the emergence of the Provisional IRA in the late 1960s.
The Fine Gael leader, Mr Bruton, last night welcomed signals that the British government planned a new inquiry. He hoped the decision "would contribute to a willingness on all sides to acknowledge past crimes and begin a process of durable reconciliation based on honest acknowledgement of responsibility".