The Labour Party has called on the Minister for Transport to reject a management buyout of Aer Lingus.
Three senior executives at the State airline yesterday put the dramatic proposal to pursue the buyout to Mr Brennan.
Last night, the Tánaiste, Ms Harney, left open the possibility that the Government would back the proposal. She said she was very impressed with the turnaround of the company by its workers and management and believed that, for its continuing success, it would need access to private capital.
She said all proposals for the airline "should be considered in a fair and objective way".
But Labour's spokeswoman on transport, Ms Roisin Shorthall, said today that "no convincing argument" had been made for the privatisation of Aer Lingus.
"Aer Lingus is of crucial strategic importance to this country as an island nation, heavily dependent on tourism and one of the few EU members without a land link to the European mainland," Ms Shorthall said in a statement.
"When the Minister for Transport, Seamus Brennan, introduced the Aer Lingus Bill last October I warned that its primary purpose was to facilitate the privatisation of the company.
"The question that now arises is, had Minister Brennan prior knowledge of this move by the three executives? Has there been behind the scenes 'tick-tacking' between the Minister and the executives, with a view to furthering the Brennan/PD privatisation agenda?" Ms Shorthall asked.
SIPTU reacted negatively to the proposal, with its president, Mr Jack O'Connor, saying the union remained opposed to the privatisation of Aer Lingus.
The proposal is likely to force the Government finally to make a decision on the issue of privatisation, something it has been shying away from for some time.
The airline was close to going bankrupt a few years ago and is one of the few European flag carriers to have bounced back from the crisis caused by the September 11th attacks and the growth of low-cost airlines.