More than 2,000 jobs in universities and colleges across London are at risk and the cuts may be the "tip of the iceberg", union leaders have claimed.
The University and College Union (UCU) said 2,165 jobs in higher education could be axed, with 2,033 of the cuts projected for universities.
Despite the recession several institutions proposing job cuts are not in financial crisis, the union claims.
Universities UK said institutions would seek to "minimise job losses".
The UCU said job losses in the capital made up a third of all total jobs going in post-16 education nationally, which stands at 5,891.
Union's job cut claims
London Metropolitan University - 550
University College London - 530
Kings College London - 390
University of the Arts London - 300
Imperial College London - 130
Lambeth College - 49
City University - 35
Southgate College - 30
The Royal College of Art - 26
Hackney College - 20
Tower Hamlets College - 16
Westminster University - 7
Lewisham College - 6
Kensington and Chelsea College - 6
Merton College - 3
Bromley College - 2
It said the five worst affected colleges were London Metropolitan University, the University College of London, Kings College London, University of the Arts London and Imperial College London.
Up to 40,000 students would be affected by the cuts as current staff to student ratios stand at 1:18, nearly double what it was 30 years ago, the union said.
The UCU's general secretary, Sally Hunt, said: "These figures offer a worrying snapshot of what is happening in the capital's universities and colleges; even more worrying is the fact that many institutions have not set out their plans as yet.
"Universities and colleges need to understand that our members will not sit idly by while their jobs or those of colleagues are axed. All institutions that are considering slashing jobs need to make a clear, transparent case for the losses and start speaking to us immediately."
The union also said: "Nobody is saying that the sector in the capital is awash with money but the fact is that universities and colleges in the capital are in relatively good financial health."
Responding to the figures, a spokesman for University College London said it was "assessing all areas of activity" to identify savings in anticipation of reduced public spending.
"We have acknowledged that redundancies cannot be ruled out," he said.
"We will of course endeavour to avoid redundancies and will seek to reduce numbers through normal turnover, redeployment, voluntary severance and early retirement. It is extremely premature to be talking about 500 job cuts."
Diana Warwick, chief executive of Universities UK, did not comment on the union's figures but said no one was "immune from the current economic problems".
"Decisions on staffing can only be taken at individual university level," she said.
"Trade unions are always involved in such discussions, and universities have a good track record in handling staffing changes in an open and fair way."
She added: "They will be seeking to minimise job losses in the face of the current challenges, and to avoid compulsory redundancies."
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