South Kent College has called in accountants and auditors to check that employment law was followed and that staff were kept properly informed during the cull of more than 50 management and administrative posts.
About 20 more managers quit as the redundancy process dragged on and their positions looked uncertain, unions said.
Pat Gorman, branch secretary of the University and College Union, said:
"Staff for some time have felt completely railroaded and thoroughly ignored.
"I hope, personally, the review will make senior management change the way they treat staff. The principal has been here two years but has put staff relations back 10 years."
The unions say the redundancies were carried out with no real consultation and have left staff with much bigger workloads.
They also questioned why the college, which has a history of financial trouble, was considering spending millions on new buildings when it was too poor to keep its staff.
"What's the point in building a new college if there's no one left to teach in it?" Mr Gorman asked.
The college principal, Tom Johnson, is abroad and was unavailable for comment.
In a statement to staff, the college said: "As part of the college's quality assurance arrangements, the governors have commissioned a review of the process supporting the restructuring. This will be led by external advisers and will start on July 31."
The college blames the change in funding priorities for its financial difficulties, which prompted the job losses, since it relied heavily on adult education, which has been cut.
Jonathan Allen, the independent clerk to the governors, said they had been assured by the college management that the redundancy procedure had been carried out properly, but they wanted impartial confirmation.
He said: "It's very rare to receive a vote of no confidence and the governing body was mindful that it had to react in a professional way.
"The governing body fully supports the restructuring as the college has gone through significant funding challenges."