British Airways’ pilots have withdrawn a threat to strike over Easter, but the airline’s threat of legal action against the union may only have succeeded in extending the pilots’ right to walk out.

The pilots will retain the right to strike following the holiday after their union Balpa went to court itself on Monday, when the High Court released the pilots from a 28-day legal deadline for action. The strike threat has therefore become open-ended.

Balpa members are furious at BA plans to employ pilots on separate contracts at start-up subsidiary OpenSkies, which will launch in June flying between New York and Paris or Brussels. They voted by an 86% majority for their first strike at BA in 30 years.

But after talks broke down last week, the airline said it would seek a court injunction as soon as Balpa named a strike date. BA hoped this would force another ballot since the pilots were legally required to take their first day of action by March 20.

BA intended to make its legal challenge under a clause in the treaty that established the European Union. Balpa will now go back to the High Court next week to seek a ruling on whether this clause can be applied to trade unions.

If the judgment is in the union’s favour, Balpa will give seven days notice of the first strike.

Balpa general secretary Jim McAuslan said: “BA should be at the negotiating table. Our row is not with the travelling public.”