Drivers at bus firm Sovereign in Edgware, London have rejected another pay offer from their bosses.
The Unite union members voted by 170 to 25 to refuse it.
They argued that the “new offer” was equal to one they had already voted against.
The drivers have rejected every offer since the company sacked their union convenor, Abdul Omer Mohsin.
Bosses have been trying to claw back every gain the union won by striking in 2009.