It has emerged that Ryanair has written to the Dublin Airport Authority accusing it of recklessly trading.
It says it will not use the planned new second terminal at the airport, adding that if it succeeds in taking over Aer Lingus, it will make sure that airline will not use it either.
In response, the DAA says carriers who oppose new infrastructure at certain periods, can quickly use that infrastructure when it subsequently suits their purposes. And it says the advent of open skies will mean more airlines using the airport.