London Underground drivers are to strike on Boxing Day, and 18 and 25 January in a row over bank holiday pay, the Aslef union has said.
A stoppage is likely to affect Tube services across the capital, causing disruption for shoppers and tourists.
An Aslef spokesman said: “The ballot result shows the strength of feeling that remains on this issue.”
London Underground’s Howard Collins said: “Further industrial action will not achieve anything.”
It will be the third successive Boxing Day walkout by Tube drivers, in a dispute over Bank Holiday pay which dates back to an agreement in 1992.
The move was announced after Aslef members voted by 9-1 in favour of strikes in a long-running row over extra pay for working on bank holidays.
“London Underground has a long-standing agreement with all trade unions which covers working arrangements on bank holidays, including Boxing Day,” Mr Collins added.
Westminster City Council said parking in the borough would be free on Boxing Day.
Conservative Councillor Daniel Astaire said: “We want to ensure that shoppers know they can still come into London to snap up those apres-Christmas bargains as well.”
BBC