Ryanair plans to challenge a ruling by Denmark’s labour court allowing industrial action against the Irish airline at Copenhagen airport in a row over its refusal to enter into collective agreements with local trade unions.

The Danish court said that members of the country’s Confederation of Trade Unions (LO) could refuse to service Ryanair flights out of Copenhagen airport, where the airline has based one aircraft.

While there is no direct right of appeal from the Danish labour court, Ryanair has lodged its own claim against the unions. It is also likely to look at other challenges, such as lodging a complaint with the European Commission.

Ryanair argued that the ruling “appeared to allow competitor airline unions” to blockade the one craft it has based at Copenhagen. Any industrial action could involve staff working for companies that service rival carriers. It is likely to be at least two to three weeks before the unions take action, which would involve ground staff refusing to handle Ryanair passengers’ baggage, fuelling its craft or providing other services to the airline.

Industrial action can only apply to Ryanair planes based at Copenhagen and not to those flying into Denmark from other countries.

Ryanair is likely to put plans on hold to add four other craft to the one already based at Copenhagen. Spokesman Robin Kiely said that it intends to continue to operate 12 routes from there, but will use planes based outside Denmark.

Danish Confederation of Trade Unions spokesman Kenneth Nielsen confirmed that its members cannot take industrial action against Ryanair services if the airline moves its base out of Copenhagen.

The dispute is rooted in Ryanair’s refusal to enter into a collective agreement with Danish unions covering staff based in the country because the airline employs staff under Irish law. Mr Nielsen explained that under the Danish model, collective agreements between unions and employers, rather than extensive labour legislation, govern workers’ rights.

He pointed that rival airlines with bases in Denmark, including EasyJet and Scandinavian group, SAS, all have collective agreements with their staff, but Ryanair does not.

Academics and industry figures recently claimed at a European Parliament committee that Ryanair’s employment practices could have implications for safety. The airline responded warning that “should they make defamatory claims about Ryanair’s safety in any other forum we will initiate proceedings against you without further notice”.