Teachers at three sixth form colleges across Sussex are set to begin the first of three one-day strikes over pay.
Around 8,000 students at Varndean College, Brighton Hove and Sussex Sixth Form College (BHASVIC), and Collyer's in Horsham will all be affected by the National Education Union (NEU) action on Thursday.
Staff at 32 colleges across England are walking out in a dispute over cuts to their pay and funding in comparison to maintained schools, the union said.
A Department for Education spokesperson said “sixth form colleges are responsible for the setting of appropriate pay for their workforce and for managing their own industrial relations".