The Public and Commercial Services union (PCS), a PSI affiliate, is campaigning for a full independent review into the impact of the privatisation of the prison service. This should include a thorough examination of the processes and financing; and the impact on prisoners, staff, communities and the public – with a moratorium on any further privatisation until it is completed.

PCS general secretary Mark Serwotka said: "We welcome the decision to strip Serco of this potential contract but it should never have been handed it in the first place.

"Privatisation of our justice system is happening without any public debate or discussion and we urgently need an independent review to look at its impact on our communities, staff and prisoners."