Guiomard also admitted that his decision to freeze passenger charges at the airport until 2009 would leave the Dublin Airport Authority (DAA) "heavily indebted" upon the completion of T2.

He also said the company would "immediately go bankrupt" if it were forced to hand over T2 without some agreement on splitting airport charges with the new operator.

"There would have to be some split between operating cost and capital costs and there may have to be a change to the State Airports Act if it turns out that T2 is not operated by the DAA, " said Guiomard.

There are fears that his decision could eventually lead to a downgrading of the DAA's credit rating, which would make it more difficult to raise finance for future developments after T2 is completed.

Guiomard said, however, that he had offered to meet credit rating agencies to reassure them about the future of the airport beyond 2010.

He said the question of how the DAA's debt would affect future developments "really starts to raise issues about where prices will be in the second half of the next decade and there's not much you can say about it. It is clear, however, that there won't be investment on this scale at the airport in the near future again".

Meanwhile, a spokesman for the DAA said it was seeking reassurances from Guiomard about whether he will increase airport charges after 2009 so it can repay its debts from the construction of T2.

"While the regulator has indicated he might approve an average airport charge per passenger of circa 7.75 for the years 2010-2014 at Dublin airport, nowhere in his long and detailed document does he give any assurance that he will do this, nor does he rule out changing many of the regulatory goalposts which might currently suggest such a charge, " he said.

The spokesman claimed the DAA would be forced to borrow up to 1bn to fund T2 and other improvements at the airport because the after-tax profit it made from the recent sales of Great Southern Hotels and its stake in Hamburg airport was less than 150m.

However, Ryanair's head of regulatory affairs, Jim Callaghan, described this claim as "bollocks. . .

They just don't want to spend their own money on this. They want the regulator to sign off on an increase in passenger charges, " he said.

He said Guiomard's admission that he had not considered the possibility that T2 could be run by a private operator showed the state had no intention of introducing competition at the airport.

"It is a complete and utter red herring. The reality is it will be run by no one but the DAA and the way the DAA has designed it is so that it has to use a large amount of the facilities from terminal one. It's also gold-plated so it will be impossible for anyone to run it profitably."