University strikers have turned down an agreement reached by university union leaders and employers to end the pensions dispute.
It means the strike will continue – with threats to disrupt final exams and assessments in the summer term.
University staff rejected the deal as failing to address their concerns over threats to their pensions.
The university strike is in its fourth week and has meant classes being cancelled in over 60 universities.
It began over planned changes to the pension, which the University and College Union said could mean a £10,000 per year reduction in retirement income.
An agreement between the UCU and Universities UK, announced after days of negotiations, had offered a deal – but this failed to convince a meeting of university representatives on Tuesday.
Deal turned down
"The strike action for this week remains on and we will now make detailed preparations for strikes over the assessment and exam period," said Sally Hunt, the leader of the University and College Union.
"We want urgent talks with the universities' representatives to try and find a way to get this dispute resolved."
The union has threatened a further 14 days of strikes, "designed to hit the exam and assessment periods between April and June".
A Universities UK spokesman said: "It is hugely disappointing that students' education will be further disrupted through continued strike action."
He said the deal had been jointly agreed by union and employers as a "mutually acceptable way forward".
The deal proposed temporary pension arrangements, with higher contributions from staff and universities, with talks to be re-opened on longer term ways to make the pension sustainable from 2020.
There would also have been an independent re-evaluation of the pension scheme – after the union's challenge to University UK's claim of a £6.1bn projected deficit.
But this agreement has been rejected by a meeting of the union's representatives – with warnings that it was "completely unacceptable" after weeks of strikes and loss of earnings.
An open letter from staff opposing the deal had argued that it was only postponing long-term decisions about the pension scheme and called for industrial action to continue to "force a more decisive victory".
Universities UK had warned vice chancellors that if the agreement was not accepted, the previous pensions proposal would be reinstated, with the "likely outcome" that there would be more strikes in April and May.
The universities minister Sam Gyimah has called for students to be given refunds on fees for lost teaching time.