Chambers Ireland says €500m has so far been wasted by delays.

The Government is making last ditch attempts to get Aer Lingus ready for a June sell-off date.

The main elements of a package designed to solve the airline's looming pension deficit are close to agreement and if they can be signed off this week the main decision on a flotation could be taken on April 4th.

Government sources yesterday denied reports that a decision had been taken to shelve the privatisation until September. However the window for a June sell-off is rapidly closing. The Aer Lingus chief executive Dermot Mannion has said that unless a decision is taken in March, getting a sale completed by June would be difficult.

The pension negotiations, which involve unions Siptu and Impact, are proving difficult and complex. The Department of Finance does not want too much of the sale proceeds to be used to shore up the Aer Lingus pension fund, which is also used by workers from the Dublin Airport Authority and SR Technics.

With the Department of Finance maintaining this stance it is possible the staff and company will also have to make greater contributions in future.

A summer sale is seen as highly unattractive because leading fund managers in Europe and the United States are often not available. A sale in early July would be problematic because of the Independence Day holiday in the US.

Yesterday Chambers Ireland said all the delays had cost Aer Lingus €500 million. Its Air Transport Users Council called for the immediate part-privatisation of the airline to ensure no further money was "wasted due to political interference and union-inspired delays".

Seán Murphy, director of policy at Chambers Ireland, said: "Had Aer Lingus been allowed to fund the aircraft purchases it wanted to make under Willie Walsh's leadership, then they would have cost €1.5 billion instead of the €2 billion figure now quoted."

"Government indecision and union delay tactics have cost the company € 500 million - which equates to six years of current Aer Lingus profits. While our national airline flounders with diminishing profits, Ryanair has grown to a company that is more than six times its size," he commented.

"The privatisation process must move ahead without delay, thereby ensuring that no unnecessary costs are imposed on the exchequer to secure the future of the airline. However, Ireland currently enjoys competitive advantage with Aer Lingus's preferential landing slots at Heathrow airport . . . the Government should protect these slots."