Staff at Middlesex University will not receive their pay rises this week.
All academics are due to receive a 3 per cent rise on August 1 as part of the three-year deal negotiated nationally last year by the University and College Union. A further 3 per cent rise is due in May 2008.
But Middlesex has told staff it does not yet know whether it can afford this year's increase.
In a message to staff, vice-chancellor Michael Driscoll said that a governors' meeting held last week had concluded that "staff pay rises for 2007-08 could not be implemented until they were confident of the university's ability to afford each stage of the award".
He added that numbers of students enrolling in September would be "crucial" to giving the governors confidence that the salary increases were affordable.
The governors will consider the issue again on October 8.
Malcolm Keight, UCU's head of higher education, said: "If a higher education institution is in serious financial difficulties, it may defer payment of pay rises for up to 11 months to avoid job losses."
A spokesperson for the university said: "Middlesex has paid its staff all the stages of the National Pay Agreement to date and expects to be able to meet the remaining stages, subject to confirmation of future income."