As cabin crew at British Airways prepare for a new strike ballot beginning next week, Unite’s new militant leader, Len McCluskey, warns families not to book holidays with the airline as a positive vote for industrial action threatens Easter, the half-term school holidays and even the Royal Wedding.

The fresh ballot begins on 21 December and will continue through to the same date in January. Unite has already given BA the required notice that it will be balloting members. Following the end of the vote, the union will have to give a seven day notice period of intention to strike after which industrial action can take place over three months without the requirement for further balloting.

This would mean the Easter holidays and Prince William’s wedding could well be under threat. Officials at Unite have indicated that action over the holiday week has not been ruled out. Mr McCluskey has said he has no intention of being held back by the UK’s strike laws and is well known for his comment that he does not believe there can ever be an irresponsible strike.

David Cameron, the prime Minister, has told parliament that he thinks Mr McCluskey’s attitude is completely wrong, adding that it is a world gone mad when a militant is put in charge of one of the most powerful unions in the country.

Meanwhile, BA bosses have said that the airline is determined to keep services running as usual out of both Gatwick and City airports in the event of a strike as well as all long-haul services out of Heathrow.