London: British Airways will take legal action to try and prevent cabin crew strikes due to start next week, the company said on Friday, 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.

Meanwhile, volcanic ash may force British airports to close again next week, the country's Department of Transport said yesterday.

If a volcano in Iceland continues to erupt at current levels and if current weather conditions prevail, air travel in Britain could be disrupted between today and Tuesday.