Thousands of lecturers have been unable to take up posts at further education colleges because of the massive backlog in staff checks by the Criminal Records Bureau.
According to the Association of Colleges, FE colleges have been pushed to the back of the queue for processing applications for CRB clearance, with some institutions reporting up to 40 outstanding checks.
Meanwhile, more than 10,000 students on courses requiring childcare or general-care work placements will have their studies delayed for months while they too wait to be cleared by the CRB.
AoC officials are furious because they warned the government about the problems nine months ago. The CRB was asked to appoint more staff and invest in an IT solution to process the checks.
The AoC said it had received hundreds of calls from colleges facing delays. Ivor Jones, the AoC's director of employment policy, said: "We expressed concerns back in January, and then expressed severe concerns in May. Yet we still find ourselves in this very difficult situation."
The backlog in schools forced education secretary Estelle Morris last week to drop a ban on teachers working before their checks were completed.
But many colleges are reluctant to allow unchecked staff to teach and have been warned by insurers that they will not be covered if they decide to do so.
"As responsible employers, colleges have to determine that if they allow people on site who have not been checked, what measures they have to ensure the safety of students and staff. We are left in a position where the failure of a government agency has caused colleges severe problems at a time when they are struggling to recruit students," Mr Jones said.
AoC chief executive David Gibson said: "We are extremely disappointed to see the education of students across the country badly affected by a problem that was anticipated and could have been avoided. Although the CRB has now taken on more staff, the AoC believes this is too little too late."
A Home Office spokeswoman said the government acknowledged from the outset that there were "teething problems" with the checks and made plans to tackle them. She said: "There is not a queue for the checks as such. The Department for Education and Skills identified 22,300 checks that were urgent because of the deadline of the beginning of term. Those were a priority. Obviously, there are lots of other checks still coming in, and the turnaround time is five to six weeks."