BA cabin crews and London Underground drivers are threatening to bring the capital to a halt with industrial action on the day of the Royal Wedding, the UK's tourist highlight of the year.
One official of the Unite union told The Sun newspaper that cabin crews' next wave of strikes is set to include 29 April when Prince William marries Kate Middleton. He said: "We don't want to do it, but if it has to be done to solve this dispute, so be it."
The stand-off between the UK's largest union and BA has now entered its third year, with no sign of it being resolved following more than three weeks of industrial action last year. Unite recently confirmed that it was pursuing a high court action against the airline over the withdrawal of travel perks from employees who took part in walk-outs.
It is also awaiting the result of a fresh ballot, which is due next week. If staff vote for industrial action, strikes could begin as soon as the end of January.
But the Unite statement came only hours after Steve Grant, Aslef's London negotiating officer, told the Daily Telegraph, that it too was ready to stage a walk-out on the day of the Royal Wedding.
Aslef drivers, who account for more than half of the total employed by Transport for London, are demanding triple pay, which would see them earning £495 for a shift rather than the usual daily rate of £165, and a day off in lieu for working on a public holiday.
A spokesman for Prime Minister David Cameron branded the plans as a "cynical attempt to undermine a day of national celebration", while London Mayor Boris Johnson tweeted: "Can't believe this. Surely not!"
But Aslef would need to undertake a new ballot to stage any strike and, while Grant suggested that more industrial action was possible, Keith Norman, the union's general secretary, played down the risk of a stoppage, insisting that no final decision had been taken.
The threat of a walk-out was condemned by Mike Brown, London Underground's managing director, however. "Tube drivers already have very fair levels of pay and get around seven weeks holiday a year, including an allowance for bank holidays. The Aslef leadership is tearing up long-standing agreements that cover pay and annual leave and demanding even more – triple time and another day off," he said.