Ryanair is set to launch complaints against airlines and publicly-owned airports across Europe if it loses a landmark European Commission ruling this week.
The Commission will decide tomorrow whether the airline should repay the several million euro discounts it received at Belgian regional airport Charleroi.
Sources have reported that Ryanair will be ordered to repay about 25% of the supports - up to €7m - received as reduced landing fees, marketing, and ground handling charges.
Ryanair has said such a decicion will affect other carriers and airports, who will also be exposed to the prospect of retrospective repayment claims.
The airline said that the Commission approved this type of arrangement in July 2001 and that any alleged aid has already been passed along to consumers in the form of hugely-discounted prices.
Ryanair said that it and other airlines will be forced to re-assess the viability of all routes involving State airports throughout Europe, and warned it would make complaints against every airline and publicly-owned airport that either gave or received discounts.