The Minister for Transport, Mr Brennan, has claimed new figures given to him strongly support the break-up of Aer Rianta and contradict the findings of a report released this week by the unions.
Following the release of a report by Mazars and Farrell Grant Sparks, Mr Brennan and the unions remain deeply divided over the controversial proposals.
ICTU general secretary Mr David Begg has told the Taoiseach and Mr Brennan this week that, based on the Mazars and Farrell Grant Sparks report, the break-up should not go ahead.
But speaking to The Irish Times before the Airline of the Year Awards, the Minister said he did not accept this analysis.
"I have asked PricewaterhouseCoopers, who advise the Department, to work up their response to that report and tell me their thinking," he said.
In the meantime, other fresh information had been submitted to the Department, he said.
"Pricewaterhouse have, in the last few days, given me additional information which expresses the view that the restructuring of Aer Rianta is the right thing to do and I hope to publish that shortly. It also tells me that Shannon, Cork, Dublin, all three, will be viable.
"I'd like to remind everybody this is Government policy. It is firm Government policy and the reasons are Shannon, Cork, no longer need to play second fiddle to Dublin. They need their independence, so they can grow those airports.
"The people in the regions want that and I am determined they will have that freedom to grow those airports strongly and bring in new airlines," he said.
Asked for his views on the Mazars/Farrell Grant Sparks report, which said the break-up plan was not convincing, Mr Brennan replied: "Well that has been the view of the trade unions involved for a long time and what the report does say is they are not convinced, it does not go as far as to say this will not work. The PricewaterhouseCoopers document I will be releasing in the next few days does demonstrate the opposite to what these consultants are saying."
Mr Brennan was speaking at the Airline of the Year event, sponsored by the Chambers of Commerce of Ireland. British Midland won the title of airline of the year. The annual awards are organised by the chamber's air transport users' council and the winners were selected following a survey by MORI of 500 firms.
Mr Brennan also criticised Ryanair chief executive Mr Michael O'Leary during his speech. He said profits at Ryanair would be "a lot higher" if the company did not take out full-page advertisements criticising the Government. He said the Government was not going to be lectured to by any "high-flying taxi driver".
Asked about his view on the stream of recent reports on Aer Rianta, Mr Brennan said: " I think we are into a stage now where every second consultant has a different view. I am totally convinced, as are the Government, that strong regional leadership, a determination to grow the business, with new boards which are high-profile, respected boards, is the only way to secure the future of Shannon and Cork."
Fears for future of development body, page 3