Around 460 bus workers at First in Aberdeen are balloting for strike action over pay. The ballot includes drivers, mechanics and cleaners in the Unite union.
They are angry that management have refused to make a pay offer for this year.
The First workers held solid strikes over last year’s offer in the run up to Christmas and forced concessions from the company.
Unite branch secretary Bob Fothering said he expected a fresh wave of strikes.
The ballot results will be announced around 7 July.
Bus drivers at Sovereign Transdev’s Harrow garage in west London have voted by 76 to 3 in an indicative ballot for strikes.
The vote comes amid a breakdown of industrial relations in the garage.
The latest incident involves the sacking of a driver who was a union activist.