A BAN forbidding prison officers standing down from certain duties is akin to “modern slavery,” their union said yesterday.

Lord Chancellor Liz Truss went to the High Court on Tuesday after the Prison Officers’ Association (POA) issued a circular telling members to withdraw from riot control duties, first aid and hostage negotiation.

A judge ruled that the protest would constitute industrial action — which prison guards are banned from taking. On Wednesday morning the POA said it would be investigating whether it could challenge any aspects of the ban. It said Ms Truss had “failed to convince the court” that the POA was already in breach of a previous injunction issued last November, when unofficial walkouts were deemed unlawful.

“The fact is the injunction will not stop violence in our prisons, the failed recruitment and retention policies nor all the other disturbing statistics that are now common knowledge such as the increase in riots, concerted indiscipline, self-harm and drug availability,” a spokeswoman for the POA leadership said.

“Perhaps we now have an employer and secretary of state that are so desperate they have reverted to a modern form of slavery.”

Industrial relations in Britain’s jails have reached breaking point because of overcrowding, the loss of 7,000 guards since 2010 and successive years of pay squeezes.

Labour MP Luciana Berger used a Westminster Hall address yesterday to demand “urgent action” against prisoner suicides.

“Prison should offer a unique opportunity to provide mental health treatment in a secure environment, yet prisoners are eight times more likely to die by suicide than the rest of the population,” she said.