Aer Lingus is to sue SIPTU over its planned industrial action which was struck down in the High Court earlier this week.
On Wednesday an injunction prevented trade union members from walking off the job as part of the pensions row.
However Aer Lingus says the the threat of the strike has left it severely out of pocket.
Industry Correspondent with the Irish Times Martin Wall outlines the reasons why the airline believes it should be compensated: