The University and College Union (UCU) has warned of three years of possible industrial unrest as the jobs at risk from funding cuts totalled 3,453.
Just over half are potentially compulsory redundancies and Barry Lovejoy, head of further education at UCU, said news of further proposals to cut jobs was still coming in.
The Association of Colleges (AoC) has warned that the cuts of pound;340 million could lead to 7,000 redundancies.
"It has the feel of a return to the worst days of the 1990s, where there was an explicit squeeze on funding, and a clawback unless colleges took action on changing contracts," said Lovejoy. "It has the potential to undo the work of the last 13 years."
He added that the union and the AoC had produced guidelines on how to approach the need to make redundancies, which made early consultation with staff a priority.
But he warned that some colleges were making bigger cuts than the funding reduction warranted, arguing that this was premature. Others, he suggested, might be making savings to build up reserves so they would be in a position to rescue colleges in financial difficulty.
Mr Lovejoy said colleges were also reducing costs by replacing lecturers with "associate teachers" with fewer qualifications and lower pay, and by downgrading staff contracts. "These issues are going to determine industrial relations for the next two or three years," he said. "This is the first wave."
A survey by Unison, which represents thousands of support staff in colleges, found that 70 per cent of colleges planned to sack staff and 76 per cent were cutting courses. Dave Prentis, the union's general secretary, said: "This will have a huge impact on those who have lost jobs during the recession and are trying to re-skill. It will have a knock-on effect on opportunities available for the `lost generation' of young people, who are among those hit the hardest."
Northumberland College last week held the first strike since colleges received their funding allocations and began planning for reduced staff numbers in September.
Rachel Ellis-Jones, the principal, said the North East faced "particularly acute" cuts. The college has to reduce costs by pound;1.3 million - about a fifth of its public funding for adult students - and proposed cutting 68 of 550 jobs while changing pay and working hours for those who remain.
"Funding priorities are being drastically altered and colleges are being forced to deliver more for less," she said. "In a national environment of significant cuts, doing nothing is not an option. The proposals we have put forward would ensure we continue to deliver high-quality training while protecting the maximum number of jobs."
But she said the union had made alternative proposals, which could lead to meaningful negotiations.
Eleven colleges in London have also voted for strike action, due to take place on May 5. They face cuts ranging from 23 jobs to 130 redundancies in the most severe cases.
At The Manchester College, 250 staff are expected to be lost, partly to make its prison education contracts viable. It is also trying to fund a pound;50 million capital programme.
Others are involved in complex restructuring that may mean final job losses are not as great.
Tresham College of Further and Higher Education, for example, is planning 150 job losses, despite cuts at the lower end of the scale at 10 per cent. But it says the jobs are hourly-paid support roles and it intends to create 69 new posts to replace them.