Colleges in England say they are having to expand class sizes and hire exam halls to cope with a rising number of pupils taking compulsory GCSE resits.
Some are rehiring former teachers, according to the Association of Colleges (AoC), as an extra 60,000 students prepare to resit English and maths, many of them in two weeks' time.
Changes to grading this year meant a higher proportion of students failed.
The government says it is investing more money in colleges.
