They say they have been given just three working days to decide whether to accept their offer.
Letters have gone out to staff ahead of the bank holiday. Staff say they are "appalled" at the scale of cuts and the process of reducing the workforce.
Up to 500 people – equating to a fifth of staff – could be made redundant as the university halts student recruitment to 138 courses, amidst a £20 million deficit and 10 per cent fall in UCAS applications.
The university has a major presence in Wolverhampton city centre and large campuses in both Walsall and Telford as well as a presence in Stafford.
The university has put a 'voluntary resignation' scheme into place called Mars – a mutually agreed resignation scheme – with staff told the terms would be better than compulsory redundancy.
Staff were told they would find out if their applications would be accepted in the week beginning May 30.
Many of the job losses are within the arts after around 140 courses were halted, a number that rises to more than 400 when part-time, foundation and postgraduate courses are taken into account. Deputy Vice Chancellor Professor Julia Clarke told a meeting of staff and students that the decision was taken on economic grounds.
Letters of acceptance were sent out to staff in the School of Performing Arts from 4.30pm on Wednesday afternoon and some received them as late as 11.30pm, while others were not told until the following day on the bank holiday. However, staff have only three working days to decide whether to accept or decline the offer.
Dr Catherine Lamond, chair of the UCU negotiating committee at the university, said: "Staff are appalled at the scale of the cuts and worried people applied for voluntary severance, not because they want to, but because they have to.
"There's a mutually agreed severance scheme but it's quite heavy-handed and we're worried about compulsory redundancies. Lots of people will go and what happens to those who are left?"
Students currently on courses which will stop recruitment will be taught out of their courses, but their studies could be put in jeopardy by job losses.
Student recruitment has so far only been called a temporary measure for the academic year starting September 2022, but significant job losses in departments could ensure these subjects stop for good.
A Wolves UCU representative said: "I've worked at other places but never seen anything like it.
"We are extremely concerned about our students and staff across the university, but especially where concentrated areas of courses have been suspended and staff have been encouraged to see MARS as a better offer than redundancy.
"As far as we are aware, in the School of Performing Arts where all courses have been suspended to new students, the vast majority of staff who applied have been offered MARS.
"If everyone who was offered it feels that they have to take it, in just over two months' time the students will lose access to whole subject areas, key employability and pastoral support.
"These are the things that brought them to study with us. Students are midway through these degrees - they would have to employ visiting lecturers on hourly contracts to teach them out.
"Our members are torn between worrying about their students and having to decide what to do, all while getting devastating emails late at night.
"We are concerned not only about our current undergraduate students, but also our postgrads who are midway through their masters and doctoral degrees. Who will supervise and mark their projects now?
"Our members care deeply about the value of education to change young people's lives and are experts in supporting students in complex circumstances to achieve their full potential. All this is being lost."