The Mayor of Copenhagen, Frank Jensen has banned the city's 45,000 officials from flying with Ryanair - even when it is the cheapest option.

This is a protest against the wages paid by the airline and the lack of a Danish collective-bargaining agreement.

In March the Irish airline's first flight from Copenhagen was grounded for three hours amid a dispute with unions over wages and working conditions.

Speaking to a Danish newspaper, he said that in Copenhagen "we have fought hard against the scourge of social dumping."

This is defined by the European Commission as "where foreign service providers can undercut local service providers because their labour standards are lower."

A spokesman for the airline said: "We are surprised at Mayor Jensen's comments which don't take account of the fact that Ryanair's pilots and cabin crew enjoy high pay, job security and already have a collective agreement with Ryanair.

"We are also surprised at his boycott call when all Ryanair flights in Copenhagen are being handled by workers who are represented by Danish unions. Ryanair is growing tourism, traffic and jobs in Denmark."

Ryanair has not entered a Danish collective bargaining agreement with a union for pilots and cabin crew - Ryanair and the Danish Confederation of Trade Unions will talk this week about whether the company should adhere to Irish or Danish rules at the Copenhagen base.

Last month, Ryanair announced that it would expand its Danish operations to include new direct flights to Budapest, Malaga and Alicante.