Inspectors have heavily criticised one of Britain's toughest young offenders' institutions, saying it has disgraceful squalid conditions.

Senior staff at Portland Young Offenders' Institution told prison inspectors that the condition of the 19th century centre in Dorset was a "moral outrage" following years of neglect.

Young offenders told of rats in a food service area and inspectors found toilets in some of the wings smelled foul, showers were stained with years of accumulated filth, and areas stank of damp and urine.

The report by the Inspectorate of Prisons also found conditions on some of the wings were "dangerously unhygienic", with tables covered with filthy towels.

And it said some of the staff were in a "time warp".

Top quality playing fields had been fenced off for security reasons, and nothing had been done to make use of the vast areas of waste ground within the prison perimeters, according to the report.

Chief Inspector Sir David Ramsbotham said: "Some members of staff have served at Portland for more than 25 years and it tells.

"They are in a time warp as far as change and appropriate treatment of young prisoners and children are concerned.

"It remains a fundamental question as to whether a remote convict prison built in 1848 was an appropriate place for a modern society to be holding some of its most disadvantaged children in the year 2000."

Portland's governor Kevin Lockyer, who took up his post last summer, told BBC Radio 5 Live that the report painted a fair picture of the institution but things were getting better.

"There is a need for staff at Portland to be more proactive about the way in which they deal with the young men they have got here and the problems that they face," he said.

He said he was trying to move Portland, which can hold nearly 600 young people aged between 15 and 21, away from its very rigid and militaristic past.

But campaigners for penal reform said children should no longer be sent to Portland in light of the report's findings.

A spokeswoman for the Howard League for Penal Reform said the whole regime should be changed, because it was not a safe place to put children.

"What the Howard League would like to see is an inquiry which will look back over the history of Portland to see whether criminal prosecutions ought to be brought against staff or not," she said.