Copenhagen’s mayor Frank Jensen has banned all city staff from flying Ryanair for official travel.
It means around 45,000 employees are no longer allowed to use the carrier for work trips.
The mayor said the ban was imposed because Ryanair does not pay its staff properly and because it won’t sign a Danish collective bargaining agreement.
"Here in Copenhagen we have fought hard against the scourge of social dumping," he told Danish newspaper Berlingske.
"Therefore we require all of those who deliver services to the municipality, including those who would sell us plane tickets, to offer their employees proper salaries and working conditions.
"Our rules mean that we cannot enter contracts or buy goods from suppliers that do not pay proper salaries."
A Ryanair spokesman 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 at a time when SAS is cutting flights, closing routes, cutting pensions, cutting pay and cutting
jobs. Which model does Mayor Jensen prefer to support? SAS¹s jobs cuts, pension cuts and pay cuts or Ryanair¹s growth?"
