Prisoners covered gaps under cell doors with cardboard and towels to prevent a rat infestation at a failed prison where special precautions were taken by a guard dog, a report said.

Chief inspector of prisons Charlie Taylor said the smell of rat urine was “very strong” in some areas of HMP Rochester in Kent.

A report published on Tuesday detailed “poor” and “decrepit” conditions, increased violence, self-harm and widespread drug use, prompting the watchdog to call on the justice secretary to make major improvements to the lower-security prison. A category C prison in England and Wales where so-called urgent notification is made.

Designed to prepare reformed criminals for life outside prison when they are released, the training and resettlement prison houses more than 700 men in the UK’s first borstal – youth detention facility – with some accommodation dating back to the late 19th century.

Bedford, Bristol, Exeter, Manchester, Wandsworth, Winchester and Woodhill prisons are among nine prisons that have received urgent notice since November 2022, along with Cookham Wood young offenders institution.

Mr Taylor said after the last inspection in August that the Rochester prison was ordered to close several years ago but remained open because of the prison overcrowding crisis.

Despite this, the underlying problems “have not gone away” and there has been a “shocking level of neglect” and a “decade-long decline” at the prison, which has “consistently failed” in five inspections since 2013.

Drug use was “endemic” and the number of violent attacks on staff was increasing, the findings found.

The report said the dilapidated prison had “fundamentally failed in its rehabilitation purpose as a category C training and resettlement prison”, with some of the worst conditions inspectors had seen in recent years.

“Staff and prisoners told us that rats and mice regularly entered the cells and offices in the old wings.

“Prisoners resorted to creating barriers of cardboard or towels to fill gaps under cell doors to keep vermin out,” the report said, adding: “The smell of mouse urine was very strong in some areas.

“During the inspection, both staff and prisoners complained about the infestation.

“Staff showed us where the rats were getting in through drains and around pipes.

“It was clear that rats were also commonplace, and in some wings almost all prisoners placed makeshift barriers under their cell doors to keep the rodents out.”

Andrea Coomber, chief executive of the Howard League for Sentencing Reform, said: “This report into Rochester prison highlights the appalling situation the current Government inherited when taking office. But it also highlights that Government ministers can only use this as an excuse for so long.”

He welcomed recent efforts to tackle problems in prisons but warned: “If a year later we are still seeing inspection reports like this, then it will be the Government’s sole fault.”

In September Prisons Minister Lord Timpson insisted urgent improvements were made to tackle drug problems and “dangerously high levels of violence”.

He said: “We are taking immediate action to improve conditions at HMP Rochester, offering additional support to our hard-working staff and addressing the drivers of violence.”

A Ministry of Justice spokesman said security measures would be reviewed, greater efforts would be made to include prisoners in education and training, and cells would be renovated.