The trade union Unite has thrown a spanner into the works of its ongoing negotiations with British Airways by announcing plans to mount legal action over the airline’s removal of travel concessions from cabin crew who went on strike.

In a statement, Unite, which represents 11,000 cabin crew at the airline, said the management’s action was a breach of European Human rights legislation.

The union said it is also preparing to provide additional assistance to members who have suffered particular financial hardship as a result of BA docking additional days’ pay from those who went on strike.

The move follows the union’s rejection last week of BA’s “final” offer.

BA said it had acted properly in withdrawing the benefit.

A company statement said: “Staff travel is a non-contractual perk that the company can withdraw at its discretion. Our cabin crew knew that if they took part in strike action, they would lose their staff travel perks.

“We totally reject the claim from Unite and will defend our position vigorously.”

The dispute began over changes to working practices, but has shift to the so-called travel perks, which entitles staff to a certain amount of heavily-discounted travel.

BA initially withdrew them from staff who went on strike and although it later reinstated the concession, it said it would not allow staff to keep their length of service entitlement.

Unite’s joint general secretaries, Tony Woodley and Derek Simpson, said: “Unite remains determined to secure a settlement to this dispute acceptable to cabin crew.

“We will continue to support our members financially and legally to ensure that every avenue is explored to achieve justice for these loyal and professional men and women who have been so badly treated by their employer.”

Union leaders are planning to meet BA executives next week at the conciliation service Acas for further talks to resolve the still unsolved dispute.