Lecturers at Tower Hamlets College, east London, have begun a continuous strike in a bid to prevent job losses and cuts to English language classes.
On the first day of enrolment last week, staff walked out in protest at plans that they say will cut 1,000 places on English courses and mean the loss of 13 jobs, or just under seven full-time equivalent posts.
Alison Lord, branch chair of the University and College Union at Tower Hamlets College, said: "It is a shame that things have come to this. We had no desire to take strike action but what the college is planning is totally unacceptable.
"We have 800 students on waiting lists, so to cut English classes like this will hit some of the most vulnerable people in London."
The strike for an "indefinite" period is the culmination of a dispute that broke out in June when staff learned of planned cuts. At the time, it was thought 25 full-time posts were at risk, although this has fallen.
Michael Farley, the college's principal, condemned the strike as "irresponsible action" but said they would try to ensure that it did not disrupt students' access to education.
"Many of our local residents have battled through numerous obstacles for their right to education," he said. "Negotiating a picket line is an unfair and unnecessary barrier.
"Strike action at this economically sensitive time could have a severe impact, threatening the future viability and long-term reputation of the college and resulting in significant implications for all staff."
Mr Farley said the college had lost pound;1 million in learner-responsive funding over the last three years and, although the college had covered the cost of unfunded courses from reserves, it had become unsustainable.
English language classes remain the college's largest curriculum area, with 2,000 students starting from this month, representing 43 per cent of the entire student body.