Staff will walk out for three days as part of national strike action organised by UCU (University and College Union), over disputes relating to pay, working conditions, and pensions.
However, union members said they were "disgusted" by the "threatening" tone of an email sent by HR at the university which asked staff to reschedule classes affected by strikes, meaning they would do their work unpaid.
The union also claims that the email "threatened to deduct up to 100 per cent of pay for taking Action Short of a Strike (ASOS) which at the moment is working to contract - this is illegal."
UCU is asking its members to take continuous ASOS from Wednesday, which means only working to contract hours.
Staff undertaking ASOS therefore do not undertake any voluntary activities, do not cover for absent colleagues, do not reschedule lectures or classes cancelled by strike action, and remove online materials associated with classes cancelled by strikes.
A UCU member who wished to remain anonymous said: "This is an atrocious threat because it acknowledges that in order to deliver high quality teaching, staff must work beyond their contracted hours.
"It's especially bad for temporary staff who are only allocated so many hours per week and regularly work beyond their hours and are therefore unpaid for all of that labour.
"This includes marking, meetings, teaching, teaching preparation and personal tutoring."
The email also told staff to inform the university beforehand whether they were going to strike - which is not a legal requirement.
However, the university has since said that it has communicated to staff that they are "under no obligation to inform the university of this in advance".
Dr Catherine Lamond, chair of UCU at the university, said: "Members of staff at the University of Wolverhampton were shocked by the threatening email sent from HR in advance of strike action.
"Our industrial action is legal, justified and necessary. HR said ‘Colleagues are also reminded of the duties of cooperation and faithful service that are implied in all contracts. It is expected that you will efficiently perform your duties without seeking to disrupt the institution. We expect that staff members will continue to work efficiently as usual.’
Dr Lamond added: "This sounds like something from Downton Abbey, not a higher education institution in the 21st century. For industrial action to be effective and lead to resolution of the dispute, which is what we all want, it needs to have an impact, so continuing ‘to work efficiently as usual’ would be pointless. We will lose pay for strike action and we are entitled to withdraw our labour."
She added: "The email from HR states that everyone should reschedule their classes, meaning they expect us to do all our normal work but not be paid for it.
"Management are asking people to confirm in advance if they will be on strike, but members do not have to give their employer notice of taking strike days.
"Some managers have also said that strike action will lead to a break in pensionable service, which is not correct. They are also threatening to deduct up to 100 per cent pay for taking Action Short of a Strike (ASOS) which at the moment is working to contract – this is illegal.
"Finally, management have kept very quiet about the fact that they have not given staff the 3 per cent pay uplift agreed with the national body UCEA in August.
"I and many of my colleagues are disgusted by this intimidatory approach from senior management. If they thought it would frighten people into reconsidering taking industrial action, that was a big mistake because it has backfired, with many members contacting me to say that this threatening approach has strengthened their resolve to support UCU’s ASOS and strikes."
Aisla Nicholls, acting director of HR at the university, said: “The University of Wolverhampton has been informed by the Universities and College Union (UCU) that its members intend to take industrial action on Thursday 24, Friday 25, and Wednesday 30 November 2022, in disputes relating to pay and working conditions and the USS pension.
“This is a long-running national dispute which is affecting over 150 universities across the country. We recognise and respect the right of staff to take this action.
“We have communicated that staff who choose to strike are under no obligation to inform the university of this in advance. In order that we can make appropriate pay deductions, we are asking all colleagues to inform us whether or not they are participating in strike action (and action short of strike) by the 3 December, so after the strike dates.
“The university will remain open throughout the strike action and our aim is for activities and facilities to run as close to a regular service as possible, to try to ensure that disruption to students is kept to a minimum.”