Hundreds of bus drivers are to launch an all-out strike later this month in a dispute over pay and conditions.
Members of Unite employed by Go North West in Manchester will walk out from February 28.
The union claims the company is threatening to fire and rehire workers on inferior contracts.
The workers voted by 4-1 in favour of strike action earlier this week.
Unite regional secretary Ritchie James said: “Unite gave Go North West the opportunity to withdraw its fire and rehire plans following the overwhelming vote for strike action, sadly it spurned this opportunity.
“As a consequence, Unite has had no option but to call its members out on strike.
“This will inevitably cause a great deal of disruption throughout Greater Manchester and beyond, but I hope that passengers appreciate that Unite took this action as a last resort.
“If Go Ahead were allowed to implement its fire and rehire policies it would result in our members, who have been in the frontline since the pandemic began, having to work longer for far less money.”