UCU union members at Lambeth College are balloting for fresh strikes.
The workers are in dispute with college bosses over a series of attacks including imposed new contracts and changes to lesson observations.
UCU members struck for over five weeks last term against the contracts.
The ballot ends on Monday of next week.
Lambeth College workers and supporters were set to protest at the college’s Clapham site on Tuesday of this week. London Region UCU called the protest.