Prison officers have mounted an illegal strike at HMP Liverpool following the dismissal of a member of staff for use of force on a violent inmate.

Staff at the crisis-hit jail have said the decision to sack the male prison officer over his use of “pre-emptive force” during an altercation with a prisoner in January 2018 has left them feeling unsupported at a time when assaults in jails are at a record high.

Mark Fairhurst, national chair of the Prison Officers Association (POA), told The Independent such decisions were "forcing staff out of the service".

“The staff want assurances from the governor that quality will be adhered to and that if they deliver a pre-emptive strike on a prisoner and it is reasonable and proportionate they will be supported and not disciplined,” he said.

“But so far, the governor has refused to give those assurances. We are seeing a rise in violence against our members – with a record high of 27 a day getting assaulted – we feel we deserve that support. Yet all they want to do is sack us.”

Prisons minister Rory Stewart admits government shouldn't have cut officer numbers

Last year inspectors branded conditions at HMP Liverpool the “worst they had ever seen”, warning that inmates were living among dirt, litter, rats and cockroaches and occupying cells that are “dangerous to live in”.

Chief Inspector Peter Clarke found an environment in which drugs were easily available and violence had increased, and accused prison leaders of “abject failure” to provide a safe, decent and purposeful regime in the jail.

Government figures last month revealed that self-harm and violence in prisons had hit another record high and inmate suicides had risen considerably, in what campaigners described as a “national scandal”.

Mr Fairhurst said staff at HMP Liverpool would return to work only when the governor provided assurances over the use of pre-emptive strikes, and that the POA was calling on the government to "sit down with [them] at a national level and review the use of force policy and training".

A Prison Service spokesperson said: “It is irresponsible for the POA to encourage its members to take this unlawful action, which puts the safety of staff and prisoners at risk.

“We are urgently seeking an injunction from the courts, requiring the POA to cease its action and staff to comply with the Governor’s directions to return to work. Contingency plans have been enacted and additional staff have been deployed to Liverpool. The prison is secure and there is no risk to the wider public.