London Underground workers are to stage four strikes, including one on Boxing Day, in a row over bank holiday pay.
Aslef said its Tube members will walk out for 24 hours on December 26, January 16 and February 3 and 13 after failing to agree payments for working on Boxing Day.
Around 2,200 Aslef members were balloted, with 92% of those who voted backing a campaign of industrial action.
The union has been seeking "adequate compensation" for those working on Boxing Day, saying they had been offered no extra pay.
Aslef said it also wanted Tube drivers to be able to volunteer to work on such an "unsociable" day.
PA, photo by anish vishwanathan