London Underground train drivers have voted to strike on December 26th in a dispute over extra payments for working on the public holiday, the Aslef union said today.
Around 60 per cent of the underground system's drivers are Aslef members and the action would affect all the network's lines, a spokesman said.
If the strike goes ahead, it could hit struggling retailers hoping to attract large crowds of shoppers to traditional post-Christmas sales in central London.
Operator London Underground said the claim for extra pay was "outrageous" and went against a long-standing union agreement that staff would work as normal on some public holidays.
It said it had already reviewed the level of service needed on the December 26th holiday so that only a quarter of drivers would need to work.
Aslef said it had won a 92.3 per cent vote in favour of action after balloting the 2,200 drivers in the union. A turnout figure was not immediately available, but the spokesman said it was "exceptionally high".
London Underground was seeking volunteers to work on December 26th but was not offering any offering additional payments, the union said. Its members may require "substantial incentives" to volunteer, it added.
Further action would take place on January 16th, February 3rd and February 13th if the dispute was not resolved, the union said.
London Underground said it was "disgraceful" that Aslef was threatening a strike while talks on the issue continued.
"The threat of strike action will not achieve anything and I urge Aslef to join us in our commitment to resolve this matter through discussions," said London Underground chief oOperating officer Howard Collins.