The Unite union has called the first London-wide bus strike since 1982. It will take place on Friday 22 June and involve some 20,000 workers.
The move follows an overwhelming vote by London bus workers to strike over the refusal of bus companies to pay them an Olympic bonus.
The bus workers want a £500 bonus to compensate for hugely increased workload during the Olympic games. Passenger numbers are predicted to rise by 800,000.
Other London transport workers—on the tube, Docklands Light Railway and London Overground services—have already won bonus payments ranging between £500 and £900.
But bus companies, Transport for London (TfL) and London mayor Boris Johnson have all refused to offer a similar payment for bus workers.
A successful strike next week could lead to a London bus strike during the Olympic games themselves if bosses refuse to budge.
It could also pave the way for a wider campaign to win decent pay for London bus workers, many of whom have received below inflation pay rises for several years.