Conditions in Britain's jails have been thrown back under the spotlight with reports of overcrowding and suicide attempts at Wandsworth prison.

The chief inspector of prisons warned that hundreds of inmates must be moved out from the institution she describes as among the "most impoverished" in the country.

Anne Owers says that Wandsworth is failing to meet basic standards of decency and activity for most of its 1460 prisoners.

Inmates have warned of a risk of a major disturbance following a fire last week which left one prisoner seriously hurt and 16 prison officers hospitalised.

With jails holding more convicted men and women than their capacities allow, last week's hot weather brought tensions at Wandsworth to boiling point.

"Sooner or later there is going to be a sit-down protest or worse," one anonymous prisoner told the Press Association.

"Last week when temperatures were in the 80s people were locked up for the night at 3.30pm with no drinks or anything."

"There have been at least four suicide attempts in the last few weeks."

"There are 1500 prisoners here and it was meant for 1100," Zafar Rizvi, who is serving seven years for money laundering, said.

"People are getting very upset and it's all down to overcrowding."

The Home Office will be alarmed at the reports, fearing a large-scale riot could highlight the government's failure to bring down the prison population.

Last year ministers were forced to use police station cells as emergency accommodation for inmates when jails simply ran out of cells to house them in.

And the prison service's new director general, Phil Wheatley, has rejected the demand to remove hundreds of prisoners from Wandsworth, saying there was no room for them anywhere else.

"Given the prison population, the only alternative would be to hold prisoners in police cells," he said.

"This would not, for those held in police cells, provide a better regime than that available at Wandsworth."

Owers' report follows similar findings at Pentonville and Liverpool jails with another on Parkhurst prison due to be published this week.

"This is the third depressing report on an overcrowded local prison that we have published within three weeks," she said.

"Wandsworth stands witness to the damaging effects of simply cramming more people into prisons that do not have the capacity or resources to do more than contain them, let alone carry out effective work to reduce offending.

"It is part of a prison system that is coping, but at great cost to prisoners, staff and long-term public protection."