The two main lecturers' unions, AUT and Natfhe, have called for a pay increase of 23 per cent over three years - employers have offered 12.6 per cent. Lecturers have been refusing to mark exams and coursework since March after employers declined to enter negotiations.
In some cases, lecturers have even stopped setting exams, leading to the cancellation of some finals.
Sir Digby Jones, director-general of the Confederation of British Industry, accused lecturers of holding students' future to "ransom". But the AUT blamed university employers for the disruption, through failing to resolve the pay dispute over the past six months.
An AUT spokesman said: "They are the ones who refuse to negotiate, not the AUT. We stand ready to resolve the dispute today."
The National Union of Students (NUS), which originally backed the assessment boycott, said the refusal of AUT members to set exams was "extremely worrying". The president, Kat Fletcher, said: "Sitting exams is stressful, but not knowing when you are going to take them is unbearable."