Bus drivers are to stage a 48-hour strike after rejecting a pay offer.
Members of Unite working for Arriva at depots in south London will walk out on Monday.
The drivers operate routes across south and central London.
Unite said the company initially offered workers a below inflation pay deal of 1.5%, with an improved offer which was rejected.
Unite general secretary Sharon Graham said: “Arriva’s bus drivers are fed up with being taken for granted.
“This is a profitable business that can well afford fair wages, it needs to get real on the pay offer to our members.
“Our members at Arriva will have the union’s total support until the company makes a fair offer and this dispute is resolved.”
Unite regional officer John Murphy said: “The strike action will inevitably cause considerable disruption, but this dispute is entirely of Arriva’s own making.
“It has shown its contempt to a loyal workforce by trying to palm them off with an entirely unacceptable offer.”
