Bus workers in London have voted to take strike action in a row over their workload during the Olympics.
Nearly 40% of Unite members working for 21 bus companies voted 94% in favour of strike action. No dates have been set.
The union, which is asking for a £500 bonus, says bus workers are the only London transport staff not in line to receive an Olympics bonus payment.
Transport for London (TfL) said bus workers were employed by private firms who set their pay.
Dates for strike action could be announced early next week.
Unite says it expects 800,000 extra passengers to travel on buses during the Games.
It said workers on London Underground, London Overground, Docklands Light Railways, Network Rail and Virgin would all receive between £500 to £900 in extra payments.
In May, a survey of 2,955 London bus and rail passengers commissioned by the union found that 88% were in favour of Olympic bonus pay.
Peter Kavanagh, Unite regional secretary for London, said: “It’s a disgrace that London’s mayor, Boris Johnson, and the bus companies have allowed this dispute to get this far.
“Our members are only asking for an extra £17 a day which will just about buy you a pint of beer and a portion of fish and chips at the Olympics.
“Our members want the Games to be a success but their patience has run out.”
Leon Daniels, TfL’s managing director of surface transport, said: “I am not surprised that 70% of London’s bus drivers did not vote for strike action.
“That is because about 70% of London’s local bus services are not affected by the Olympic Games.
“The whole country is really entering into the spirit of the Games and the overwhelming responsible majority are pulling out all the stops to make it a huge success.
“Only Unite appears to want to exploit it by adding a further multimillion-pound burden to the hard-pressed fare-payers and taxpayers of London.”
Mr Daniels added that Unite had already negotiated binding deals for pay and conditions with each of the bus companies for this year.
“Attempting to tear up those agreements and get a new one with less than 50 days to go before the Games is completely reprehensible and out of step with every other provider of services in this city this summer.”