The Board of Visitors at Wandsworth Prison in south London also demanded that jail staff should be made to comply with the requirement to wear name badges.
The board, made up of 19 members of the public, called for the reinstatement of plans to upgrade two wings to introduce integral sanitation - dropped because money from the refurbishment budget has been diverted to coping with overcrowding.
It said conditions in A-wing, which holds 250 remand prisoners, were 'extremely poor' with slopping out, flooding, lack of showers, cockroach infestations and inadequate facilities for association. 'All are unacceptable for any prisoners - for unconvicted prisoners they are intolerable,' the board's annual report said.
Its chairwoman, Margaret Wall, said the board was also frustrated at the Prison Service's failure to deal with serious problems in the prison's healthcare centre.
On the positive side, the board praised moves to allow inmates to spend more time out of cells, the opening of a visitors' centre and the 'professionalism and humanity' of prison officers working on the segregation landing.
A Prison Service spokeswoman said plans to close A and B wings at the end of the year had been put off because of increasing demands for cell space, not because of money.
Extra funds had been spent on them and while refurbishment would not take place until next year, it would end only six months behind schedule.
She also maintained that there had been 'significant' improvements in the prison's health care. She said the Prison Officers' Association opposed name badges for security