It is understood that no further details will be given this week on the size of the golden share that the government plans to retain in Aer Lingus. The minister will simply confirm at this stage that the state intends to keep a shareholding in excess of 25%.

The announcement will also confirm that there will be a retail offering of shares in Aer Lingus through brokers, probably with a minimum investment of 10,000.

The timing of the flotation is dictated in part by a desire to get it away before the Dail resumes in October, sources suggested. The prospectus is currently in preparation and will be issued about two weeks beforehand. The flotation is expected to raise 400m to 500m, with the airline seeking a primary listing on the Irish Stock Exchange and a secondary listing in London.

Much of the contentious detail surrounding the flotation has already been hammered out, with 1,800 Siptu members in Dublin, Cork and Shannon scheduled to vote on the Labour Court's recommendation on pay and other issues between 2 and 15 September. Aer Lingus branch shop stewards and union organisers have recommended acceptance.

On Friday, the minister announced the appointment of four new directors, including three non-executives, to the Aer Lingus board. The non-executives included Danuta Gray, chief executive of O2 Ireland; Thomas Moran, chief executive of Mutual of America; and Michael Johns, representing the Employee Share Ownership Trust (Esot). Greg Sullivan, the airline's finance director, was appointed as an executive director.