Tube drivers are to vote on possible strike action in a dispute over Boxing Day pay rates.
The ASLEF union will ballot 2,200 members after it was unable to reach agreement with London Underground over “adequate compensation” for working on the Bank Holiday.
Results of the ballot will be known on December 14th.
An ASLEF spokesman said: “The union’s executive was told that negotiations with the company had failed to reach an agreement on the terms of Boxing Day working and it has now informed the company that it intends to ballot its members employed by LU for strike action.
“The union is seeking adequate compensation for members working on such an unsociable day.”
Last year drivers went on strike after calling for triple pay and a day off in lieu.
In recent months Tube unions have secured a number of concession from Transport for London, the capital’s transport authority which is chaired by Mayor of London Boris Johnson.
Last month unions agreed to recommend members accept an improved pay offer which includes an immediate 5% increase plus increases over the next three years. Unions had rejected a number of earlier offers.
In September TfL agreed to pay drivers who work during next year’s Olympics payments of at least £500 with additional payments to drivers working shifts “of a certain duration” or finishing after 01.30hrs.