The Unite union in London has launched a campaign to win £500 bonus payments for its bus drivers to cover the Olympics period.
The union is organising a series of meetings over the next three weeks to brief drivers on how they can take part.
Last week the RMT union signed a deal for Docklands Light Railway (DLR) workers that it says is worth an extra £2,500 for each of its members.
The DLR deal involves a £900 attendance bonus and a minimum of 45 hours overtime paid. RMT general secretary Bob Crow described it as “groundbreaking”.
But the RMT rejected an Olympics offer from London Underground on Monday of this week.
Tube bosses were offering £100 tied to “customer satisfaction” strings plus around £400 in extra pay.