British Airways is facing a fresh wave of strikes after its cabin crew union won a dramatic court victory, clearing the way for 15 days of industrial action, commencing on Monday.

Unite, the union, won an appeal against an injunction which blocked a planned five-day walkout this week and later confirmed that strikes will start next Monday.

Cabinet crew will take action for five days, followed by further five-day stoppages from May 30 to June 3 and June 5 to 9, threatening travel chaos for tens of thousands of passengers.

BA said it was “disappointed” with the court of Appeal’s decision, adding that it will implement its contingency plans to keep aircraft flying.

The airline is set to reveal today a huge 600 million pounds slide into the red for the year to March, bringing total losses in the past two years to 1 billion pounds after a 401 million pounds reverse in 2009.

The latest results -- the worst since BA was privatised in 1987 -- will include an estimated 45 million pounds hit from the first round fo strikes in March.

The new strikes could cost the firm another 100 million pounds in the current financial year, with Iceland’s volcanic ash cloud adding to its woes.

Unite said: “Following the decision by the Court of Appeal to overturn the injunction estraining strike action at British Airways, Unite the union confirmed that cabinet crew would go on strike for five days from Monday, may 24, as previously notified.”

Joint general secretaries Derek Simpson and Tony Woodley said: “British airways management now has a chance over the next three days to address our outstanding concerns and seize the possibility for industrial peace. We hope it has the wisdom to do so.”

BA’s lawyers said that it would consider the judgement and reserved its position on whether to seek permission to appeal to the Supreme Court.