Prison officers have begun protest action "until instructed otherwise", their union has said, including staff at Chelmsford Prison. 

The POA trade union said its general secretary Steve Gillan had called for all members in England and Wales prisons to take protest action outside their workplaces from 7am on Friday until instructed otherwise.

The POA said the action was in response to a report on Thursday by Chief Inspector of Prisons Peter Clarke who raised the alarm over the potential for a "complete breakdown" in order and discipline at HMP Bedford.

Inmates have effectively taken control at the violent, overcrowded and vermin-infested jail, the watchdog said.

And a Shoebury woman, whose son is currently serving time in Chelmsford Prison, has said prisoners have been left in cells with no communication, and no food or drink. 

She said: "I had a phone call at about 8.30am from my son who kept asking if I had seen anything on the news or new what was happening. 

"Apparently there has not been a single member of staff in sight all morning, they were fed at 4pm yesterday and have not heard a thing since. 

"My son has said it is descending into chaos, prisoners are all banging on their cells and screaming and shouting, and they are just being left to get worked up, it will end in a riot if they are not careful."

The POA said: "The unprecedented levels of violence, and failure of this Government and employer to provide safe prisons has been headline news for some considerable time.

"The rise in violence against staff in prisons is laid firmly at the feet of Government and HMPPS (prisons and probation service), who have overseen the demise of the prison service over the last eight years."