British Airways will take legal action to try and prevent cabin crew strikes due to start next week, the company said, citing an irregularity in the union's strike ballot as the basis of its case.

Unions representing cabin crew have scheduled 20 days of strike action over the next month, starting from May 18-22, threatening renewed misery for travellers already hit by walkouts and disruption caused by volcanic ash.

BA and the union representing its cabin crew had earlier in the day said they were ready for discussions that could avert the strikes, after a mediator invited the two sides to talk.

But BA, which stopped a December strike through the courts, later said there was an irregularity in how the union had conducted the ballot to strike. A similar move was used to block a rail workers' strike earlier this year.

"On this basis we have applied to the High Court for an injunction to stop the 20 days of strikes planned from Tuesday," BA said in a statement.

The Unite union denied any ballot irregularity.

"I am confident that we conducted our ballot perfectly and in compliance with the law. We'll be defending our position in court," said spokesman Andrew Murray.

Before it said it would take legal action, BA had said it expected to carry more than 70 per cent of its customers, or over 60,000 passengers a day, during five days of strike action due to start next week.

The strikes are part of a long-running disagreement over pay and conditions that stems from BA plans to save 62.5 million pounds ($93 million) a year to counter falling demand, volatile fuel prices and greater competition.

BA says it operated 79 per cent of long-haul and 58 per cent of short-haul flights during strikes in March.

But the seven days of walkouts that month still cost the airline 45 million pounds while last month's disruption as a result of a volcanic eruption in Iceland cost it a further 20 million pounds a day in revenue.

The latest bout of industrial action will see the first strikes begin on May 18 and run until May 22. Then there will be further walkouts on May 24-28, May 30-June 3 and June 5-9.

A union representing BA pilots urged the new coalition government on Friday to intervene to try to settle the dispute.

"The last three days have changed the face of British politics with erstwhile political opponents coming together for the common good," said Jim McAuslan, general secretary of the British Airline Pilots' Association (Balpa), which represents 3,000 of BA's 3200 pilots.

"We call on government to use that political momentum to help solve what are tired 1970s style industrial relations."

The pilots are not involved in the dispute. – Reuters