Advisers hired by the Government dubbed discussions about a possible sale of Aer Lingus as 'Project Egret', documents released to the Irish Independent under the Freedom of Information Act reveal.
The documents also show that just two executives from IAG - its general counsel Chris Haynes, and director of strategy Robert Boyle - helped to spearhead Willie Walsh's plan to persuade the Government to sell its 25.1pc Aer Lingus stake as part of a €1.4bn takeover bid.
The files also show how meetings between IAG and a steering group chaired by the Department of Transport intensified before the Government made a decision to sell its Aer Lingus stake last month.
IAG made its initial approach to Aer Lingus on December 14 last year and the proposal became public a few days later.
On December 22, assistant secretary John Fearon at the Department of Transport, who's responsible for areas including aviation, held a meeting with Transport Minister Paschal Donohoe regarding Aer Lingus. Later that day, Mr Donohoe also coincidentally had a meeting at Ryanair's headquarters in Dublin.
In January, IAG improved its offer for Aer Lingus, before the Aer Lingus board approved it on January 27. The following day, Mr Donohoe held a special Aer Lingus briefing for Fine Gael TDs.
The legwork in assessing the Aer Lingus proposal was being undertaken by the steering group, with the first official mention of that group dated January 13 in Mr Fearon's diary.
That meeting focused on an update on the IAG approaches, and an update on the procurement of advisers. The steering group was established by state agency NewEra, and the advisers eventually included Credit Suisse, IBI Corporate Finance, and law firm McCann FitzGerald. Another meeting of the steering group was held on January 26.
A number of meetings and conference calls were held in March with IAG in Dublin as the airline group tried to thrash out a takeover proposal that would be acceptable to the Government. That month, and in April, some of the meetings with IAG extended for whole days.
On March 4, just a week after Mr Donohoe said that concessions and assurances offered to date by IAG weren't sufficient to convince the Government to sell up, a conference call was held by the Aer Lingus steering group at the offices of McCann FitzGerald.
That meeting was attended by Mr Fearon, with IAG's Mr Haynes attending in person and Mr Boyle taking part by phone. One of Britain's top bankers, Deutsche Bank's Tom Cooper, was also involved by phone in the meeting. Mr Cooper is the chairman of global mergers and acquisitions at Deutsche.
The Government has agreed to sell its Aer Lingus stake.