Ryanair confirmed on Thursday it would sue the European Commission for not tackling the French government over reduced domestic airport charges which the airline believes favour Air France.
"Ryanair ... today lodged a case in the European Court of First Instance against the European Commission's failure to act on Ryanair's complaint about 1 billion euros worth of state (aid) to Air France," Ryanair said in a statement.
Europe's biggest low-cost carrier said in July it planned to sue the Commission for not taking action against governments it believes are giving illegal state aid to national flag carriers such as Air France, Lufthansa, Alitalia and Olympic Airways.
"We are calling on the Commission to start promoting competition and stop protecting flag carrier airlines who continue to receive unlawful state aid," Ryanair Chief Executive Michael O'Leary said.
The Commission has said in the past that it has dealt with Ryanair's complaints both fairly and in accordance with its duties and that it believes a court would uphold that view. Ryanair is no stranger to legal action. The airline is currently fighting in the Italian courts to stop planned flight cuts at Rome's Ciampino airport and challenging an EU decision to block its bid for fellow Irish airline Aer Lingus.