The third largest Danish airport has been accused of showing "unjustifiable favouritism" towards Ryanair. The Danish civil aviation authority has threatened to revoke the operating licence of Tistrup airport, near Aarhus, for favouring Ryanair over its competitors.

It authority has ordered the airport to end by October 1st a practice of taxing Ryanair 35 kroner per passenger, half the rate charged to other airlines.

"We warned the Aarhus airport several times this summer, and we will revoke its operating licence if it does not conform to international rules to treat all companies equally," said Ms Tina Larsen, of the aviation authority. "This practice represents an obstacle to competition and constitutes unjustifiable favouritism." Ryanair is already facing European Commission scrutiny and a court ruling against its commercial practices at Charleroi airport south of Brussels and in the eastern French city of Strasbourg.

Recently the Finnish consumer ombudsman warned: "Ryanair must offer passengers at least the minimum level of consumer rights. The airline's contract conditions do not meet this requirement at present."

The complaint was one of several lodged by the agency and counterparts in Sweden, Norway and Denmark in letters sent to Ryanair requesting changes in the way the airline does business. Ryanair said: "When it comes to who has been unfair to consumers, then the consumer agencies should perhaps consider the high fares monopolies previously controlled by SAS and Finnair in their markets."