The Taoiseach told the British Prime Minister he would prefer he said nothing at all if he was not going to announce a new inquiry on Bloody Sunday.

That was the moment, two weeks ago, when the British government "engaged" with the Government's assessment of the new material on Bloody Sunday and the Report of the Widgery Tribunal. It happened during a 20-minute telephone conversation between Mr Ahern and Mr Blair on Friday, January 15th, devoted almost exclusively to Bloody Sunday.

Up to that point, Mr Blair had deferred to his civil servants when Mr Ahern raised the question of the British response to the Irish Government's report. In Luxembourg and Strasbourg, for example, he had looked to his officials: "We are looking at that, aren't we?"

According to sources, it was only this day a fortnight ago, the British Prime Minister began to take a personal interest in the events of Bloody Sunday. Up to that point, the Government had been receiving sporadic reports that the British response was going the wrong way. "The system", as it was put, including the Ministry of Defence, was resisting a new inquiry. Three times during their telephone conversation Mr Blair pressed Mr Ahern for clarification on the kind of inquiry he was now seeking into those events in Derry 26 years ago today. Three times Mr Ahern told him the Government wanted a full judicial inquiry. It is understood he also told Mr Blair he couldn't live with less.

The Government's belief that the British Prime Minister engaged with Bloody Sunday that Friday was substantiated by Mr Blair's announcement yesterday. It is now known Mr Blair took copies of the Irish Government's assessment of the new evidence, plus a copy of the report of the Widgery Tribunal home with him on the last two weekends.

After the first weekend, Government sources knew they had secured the Prime Minister's engagement. Senior officials in 10 Downing Street raised a series of questions with the Taoiseach's Office about Bloody Sunday. They stressed Mr Blair was seeking answers. The Government, like its predecessor, always insisted that a full inquiry, rather than an apology, was required.

It was little wonder, then, that Mr Ahern, paid a generous tribute to Mr Blair when he announced a judicial inquiry. "I know, and probably only I know, that the British Prime Minister had to make a very substantial move forward himself based on his own judgment."

An equally generous tribute was paid to Mr Blair by former taoiseach, Mr John Bruton, who, together with former tanaiste, Mr Dick Spring, commissioned the Government's assessment of the new material on Bloody Sunday. The decision to collate a Government analysis was taken by the Rainbow Coalition when a lot of new information came to light at the time of the 25th anniversary on January 30th last year.

The primary works examined by the Rainbow Government were books by Don Mullan and Prof Dermot Walsh and reports on Channel Four News and in the Sunday Business Post. The Government also examined its own files, which included 101 statements by eyewitnesses collected in 1972.

Two officials, Mr Gerry Cribben, from the Taoiseach's Office, and Mr Eamonn McKee, from Foreign Affairs, were assigned full-time to conduct a review of the new evidence on the events of Bloody Sunday. Their editor-in-chief, as the Taoiseach called him yesterday, was Mr Wally Kirwan, assistant secretary in the Department of the Taoiseach.

The assessment was forward by Mr Bruton to Mr Blair on June 24th last, two days before the Rainbow Government left office. In his covering letter, Mr Bruton pointed out that the actions of a government, and the forces responsible to a democratically-elected government, were in a different league to the other terrible events which had occurred in Northern Ireland. He did not have the opportunity to speak to Mr Blair about the document.

Both Mr Ahern and Mr Bruton were cautious in their responses to the announcement of a new judicial inquiry. They went out of their way to suggest that, even though Bloody Sunday stood out among the many terrible events on both sides in Northern Ireland, the paramilitary organisations should now be equally willing to be open about the atrocities they had perpetrated. They were also anxious to present the new inquiry as a separate development from the all-party talks.

It wasn't lost on anyone in past or present governments yesterday that the new judicial inquiry into Bloody Sunday will be conducted under the Tribunal of Evidence Act, 1921 - the very same legislation which was produced the Beef, McCracken, Moriarty and Flood tribunals here.