The most senior official at the Department of Transport has admitted that she was aware of a threat to the Shannon-Heathrow route in June but did not tell her minister for several weeks.
The department this evening released a report it says proves Minister for Transport Noel Dempsey was not aware that Aer Lingus might move its Heathrow slots from Shannon to Belfast until the end of July.
The Government was this morning accused by Labour Party leader Eamon Gilmore of being involved in a political conspiracy to cover up advance knowledge of the move.
Mr Dempsey described this evening's publication as an "open and frank description" of the events surrounding the breakdown in communications and maintains his staff have his full support.
The report focused on the period between June 13th and the end of July this year and was overseen by the department's Secretary General, Julie O'Neill, who concluded that though she was aware of the possibility of a move by Aer Lingus, Mr Dempsey was not informed before August.
In the report, Ms O'Neill states that the decision was not confirmed to Mr Dempsey until August 3rd, when the minister met Aer Lingus chairman John Sharman and chief executive Dermot Mannion.
The report says she did not tell the minister of the possibility because she had been told by Mr Sharman that nothing was finalised and a decision would not be rushed simply because of a June 13th media report suggesting a reallocation of the Heathrow slots.
"I believe the report to be an open and frank description of what happened reflecting the integrity of the officials involved," said Mr Dempsey this evening. "I note that the report has been vetted by the independent chairman of the Department's Internal Audit Committee who is satisfied that no relevant source of factual information has been overlooked or salient information missed in compiling the report."
Ms O'Neill and the department's assistant secretary, he said, were wrong not to tell him sooner, but he maintained this evening that he still has faith in them.
"It is disappointing that this important information was not brought to my attention in a timely manner," said Mr Dempsey. "The officials involved have acknowledged that I should have been informed and have apologised to me personally. In light of this, and the way in which they have worked with me since I joined the department I have full confidence in the officials involved."
The report is unlikely to silence calls made today by Fine Gael leader Enda Kenny for the Tánaiste Brian Cowen and Taoiseach Bertie Ahern to tell the Dáil when they first knew of the Aer Lingus decision.
"Does the Government intend to introduce a working early warning system to ensure that when information such as this comes to light it is transmitted to the ministers concerned?" he asked this morning. "It seems that ministers hear nothing and in many cases do nothing and in almost all cases see nothing."