A legal bid to stop strike action at the country's main airports in the run up to St Patrick's Day is due before the High Court.
The Dublin Airport Authority and Ryanair are trying to secure an injunction against SIPTU.
SIPTU is planning a 4 hour work stoppage at Dublin Cork and Shannon airports this Friday.
Strike action is due to take place between 5am and 9am.
It's part of a long running dispute about cuts to pension benefits at Aer Lingus and the Dublin Airport Authority.
But the DAA and Ryanair claim the strike is unlawful and they want injunctions stopping the industrial action which coincides with the Ireland/France rugby match and the busy run up to St Patrick's Day.
Ryanair says if the action does go ahead it would affect 13 and a half thousand of its customers.
