Opposition leaders will challenge the Taoiseach in the Dáil tomorrow to make a public apology to former Aer Lingus chief executive Willie Walsh for accusing him of trying to "steal the assets" of the State company.
Mr Ahern yesterday refused to confirm or deny a newspaper report that he had written to Mr Walsh expressing regret at the use of the word "steal" in the Dáil last Wednesday.
A spokesman for Mr Ahern said he would not be making any comment about the Sunday Business Post report that he had attempted to mend fences with Mr Walsh.
However, Mr Ahern's extraordinary Dáil outburst will be top of the political agenda when the Dáil meets tomorrow.
Both Enda Kenny and Pat Rabbitte have indicated that they intend to demand a full retraction and an apology from the Taoiseach.
A Fine Gael spokeswoman said Mr Kenny would be returning to the issue and insisting that Mr Ahern should withdraw his comments and apologise to the former Aer Lingus boss, who is now chief executive of British Airways.
A Labour spokesman said that Mr Rabbitte would be insisting that the proper procedure for the Taoiseach would be to come into the Dáil and apologise for his outrageous and defamatory comments.
"He accused Willie Walsh of something that would amount to a criminal offence and would certainly be actionable if said outside the House."
Mr Rabbitte has also been highly critical of the Ceann Comhairle for failing to intervene to warn the Taoiseach that it was an abuse of privilege to make such a defamatory remark in the Dáil about a person who is not a member of the House.
Fianna Fáil Dublin North TD Jim Glennon said yesterday he was glad to hear of reports that Mr Ahern had written to Mr Walsh.
He said anybody who knew the Taoiseach would know that he intended no slur whatsoever on Mr Walsh's character.
"It was an unfortunate choice of words as his spokesperson said very soon thereafter. I think it has been clarified now," said Mr Glennon, who said the Opposition was making a meal out of the episode.
Speaking on RTÉ's This Week programme, he said that at the time a management buy-out of Aer Lingus was being talked about two years ago there was a strong feeling that asset-stripping was on the cards if the buy-out went ahead.
On the progress of the privatisation plans for the airline, Mr Glennon said it was his understanding that the Government had taken a decision in principle to part-privatise Aer Lingus, but the details were still being worked out.
When that process was finished, the Cabinet would take a decision on when to go ahead with the privatisation.
He said he had more than 10,000 Aer Lingus voters or pensioners in his constituency and it was his duty to represent their interests.
He claimed that the workers and pensions should be the Government's main concern in its plans for the part-privatisation of Aer Lingus.
When the time came he would vote in accordance with what his Dublin North constituents wanted from the plans.
Mr Glennon and his 10 Fianna Fáil colleagues north of the Liffey have been invited by Siptu to today's 70th birthday celebration for Aer Lingus as part of the union's anti-privatisation campaign.
Commenting on Mr Glennon's interview on This Week, Siptu national industrial secretary Michael Halpenny said: "At last there appears to be an acknowledgement from within Fianna Fáil of the very real problems the Government's policy on the national airline is posing.
"It is now time for Deputy Glennon to follow through on his comments on RTÉ and start listening to his constituents, who include many Aer Lingus workers and their families."
Mr Halpenny said that when a large public meeting was held at Dublin airport in April to hear the concerns of Aer Lingus workers and their families, not one Fianna Fáil deputy turned up, although TDs from all the other parties did so.
"Deputy Glennon and his colleagues are very welcome to attend tomorrow's celebrations and hear their constituents' views," Mr Halpenny said.
"As a union which has been involved with Aer Lingus workers for most of the last 70 years, we feel it incumbent on us to mark the 70th birthday of this successful, publicly owned company which has played such a key role in the development of the State, even if the Government chooses not to do so."