The London's High Court ruled on Tuesday that a 12-day British cabin crew strike was illegal because it included members no longer employed by the airline.
The Unite Labor Union voted on Monday to walk out from Dec.22 among its 13,000 workers, escalating a dispute over job losses and changes to working practices.
We are delighted for our customers that the threat of a Christmas strike has been lifted by the court, British Airways said in a statement after the ruling by Justice Laura Cox.
It is a decision that will be welcomed by hundreds of thousands of families in the UK and around the world, the airline added.
The High Court backs British Airway (BA) that meant that the Unite had to call off the strike, bringing relief to around one million travelers whose Christmas holiday plans were threatened by the planned workout.
Unite said the decision marked a disgraceful day for democracy and added that it will hold a fresh ballot unless the dispute is resolved.
The dispute between BA and Unite over changes to pay and working conditions has grown increasingly acrimonious.
The planned strike would have been crippling for BA, which has been one of the airlines hardest hit by the global recession because of its heavy running costs and reliance on increasingly unpopular premium fares.
Already expected to post record losses this year, analysts had forecasts losses of up 30 million pounds ($49 million) over the planned walkout period.