Prison staff in England and Wales are taking part in a large-scale protest over “unprecedented violence” in jails, the Prison Officers’ Association has said.
Steve Gillan, POA general secretary, has called for members of the union to protests outside their work from 07:00 BST on Friday until “instructed otherwise”.
Prison staff have been protesting in UK’s major cities including London, Liverpool, Manchester and elsewhere.
Prisons Minister Rory Stewart said the POA was “irresponsible” for calling for union members to protest, which he said described as illegal.
Mr Stewart said: “Prison officers do vital and important work and we urge them to return to their duty stations, in line with their obligations to the law and the prison service. We are deploying our contingency plans but, by not turning up for work, these prison officers are putting their fellow staff and inmates at risk.”