The second date is just three days before the Games begin, raising the prospect of the capital grinding to a halt while in the gaze of the world’s media.
The Unite union is seeking a £500 bonus for members who work during the Olympics.
Staff working on the DLR, Tube, Cycle Hire and London Overground have all agreed extra Olympic payments.
Although London’s bus services are regulated by TfL the drivers and other staff are employed by private bus companies.
Mayor Boris Johnson has called on employers and the union to settle their dispute and secured £8.3m from the Olympic Delivery Authority to fund the bonuses.
Last week workers from a majority of bus operators staged a walk-out, resulting in up to 70% of bus services being cancelled. Operators Arriva, Metroline and Go Ahead won a High Court injunction blocking their workers from taking part.
The union has confirmed it will “re-ballot” members at these companies in time for them to take part in the July 24th action.
Unite regional secretary Peter Kavanagh has accused operators of playing “a dangerous game of brinkmanship.”
Kavanagh added: “Unite will be at Acas next Monday ready to meet with the bus operators. This dispute could be resolved at a stroke if the operators negotiate meaningfully. Instead it looks like a coordinated attack, orchestrated by the Tory mayor, looking for a political fight with Unite and London’s bus workers. Even ‘Boris bike’ workers are getting a £500 Olympic award. There is no justification to ignoring the massive increase in workload bus workers face. They will be on the frontline, keeping London moving during the Games.
”Last week’s action was extremely well supported and workers are getting angrier by the day – there will be no retreat. Bus services could come to a total standstill just days before the Olympics if bus operators continue to turn their backs on their workers.”
Transport Commissioner Peter Hendy has previously said the cash secured by the Mayor “would allow every bus driver in London in a garage where one or more routes were affected by the 2012 Games to gain, over the 29 days of the competitions, about £500.”
