Birmingham Prison is being taken over by the government from the private firm G4S, after inspectors said it had fallen into a "state of crisis".

A new governor and extra staff are being brought in and the capacity of HMP Birmingham will be cut by 300.

It will not be returned to G4S for at least six months - until ministers feel "sufficient progress" has been made.

G4S said it "welcomed" the development as an opportunity to "urgently address" the problems.

It is believed to be the first time the government has taken over a privately run UK prison in such a way, midway through a contract, since the first one opened in 1992.

Prisons Minister Rory Stewart said: "What we have seen at Birmingham is unacceptable and it has become clear that drastic action is required to bring about the improvements we require."

The move comes after Peter Clarke, the chief inspector of prisons, wrote to Justice Secretary David Gauke detailing "appalling" failings at the jail, which G4S was awarded a 15-year contract to operate in 2011.

Mr Clarke said it was the "worst prison" he had "ever been to", telling BBC Radio 4's Today: "Surely somebody must have been asleep at the wheel."

Mr Clarke triggered the "urgent notification" process, meaning Mr Gauke has 28 days to develop an action plan for HMP Birmingham, which is only the third prison - and the first privately run establishment - to have been issued with such a notice.

In his letter, the former Scotland Yard anti-terrorism chief said there had been an "abject failure" of contract management and delivery at Birmingham, with a "dramatic deterioration" in conditions following a riot in 2016.

He described a lack of order and control at the prison, with those perpetrating violence able to act with "near impunity".

Some inmates were too scared to emerge from their cells, groups of staff had locked themselves in their own offices, and parts of the prison were found to be filthy, with blood, vomit and rat droppings on the floor.

"The inertia that seems to have gripped both those monitoring the contract and delivering it on the ground has led to one of Britain's leading jails slipping into a state of crisis that is remarkable even by the low standards we have seen all too frequently in recent years," Mr Clarke wrote.

His letter outlines the "disturbing" case of a "troubled" prisoner with personal hygiene problems, "soaked" with water from a fire hose which inmates had pointed through the observation panel in his cell door.

"We struggle to understand how staff could have allowed this appalling bullying to take place," said the chief inspector.

Inspectors also found another "distressed" prisoner sitting on "scruffy material on the springs of his bed" because the mattress had been stolen three days earlier.

'Sleeping officers'
Mr Clarke said the case typified the "day-to-day vulnerability" of some prisoners.

"It was often difficult to find officers, although we did find some asleep during prisoner lock-up periods," he wrote, adding that "ineffective frontline management and leadership" were at the heart of the prison's problems.

Under the new regime at Birmingham, Paul Newton, who has spent 30 years in the Prison Service and is currently governor at Swaleside jail in Kent, will take charge.

An extra 30 staff will be deployed at the prison, whose population will be reduced from about 1,200 to 900.

Mr Stewart said while Birmingham faced its own "particular set of challenges", it must start to "live up to the standards seen elsewhere".

"We have good, privately-run prisons across the country," he said.

The prison's Independent Monitoring Board (IMB) said that in May it was "so concerned about the unacceptable conditions" in the jail that it "wrote directly" to the minister, who responded.

Of the 16 privately run jails in the UK, G4S has contracts to operate five of them, including Birmingham. Ministers believe the others the company runs - Altcourse, Oakwood, Parc and Rye Hill - are performing well.

But in 2016 the company was forced to transfer the management of Medway Secure Training Centre to the government, after BBC secret filming showed staff allegedly mistreating children held there.

Further concerns about the company emerged last year after another undercover investigation into the G4S-run Brook House immigration removal centre, near Gatwick Airport.

Jerry Petherick, managing director of G4S Custody & Detention Services, said: "HMP Birmingham is an inner-city remand prison which faces exceptional challenges, including increasingly high levels of prisoner violence towards staff and fellow prisoners.

"The wellbeing and safety of prisoners and prison staff is our key priority and we welcome the six-month step-in and the opportunity to work with the Ministry of Justice to urgently address the issues faced at the prison."

The IMB letter in May said "put simply, the prison fails to provide a safe and decent environment on an almost daily basis".

It said specific concerns it held included levels of violence giving "cause for concern", the widespread availability of prohibited drugs and "regularly overcrowded and unfit living conditions".

The board added there were "toilets in cells with no screen, a generally dirty, poor environment, litter, objects in stairwells, broken windows, heating broken or excessive, broken showers, lack of kettles and even, on occasion, lack of kit and bedding and cockroaches ever present".

Frances Crook, chief executive of the Howard League for Penal Reform, welcomed the news but said prisoners were probably "going to be shipped out in the middle of the night" which would cause "even more overcrowding in other prisons".