New criticisms of the jail follow an earlier damning report

Chief Inspector of Prisons Andrew McLellan said conditions for some prisoners were "as bad as ever".

His report criticises slopping out, the sharing of very small cells and a lack of support for long-term sex offenders when they are ready to be freed.

Dr McLellan, who examined the prison in January, said he was disappointed following the concerns he expressed last year.

He had raised concerns at the lack of preparation long-term sex offender inmates are given for their release back into society.

The cells are also among the smallest in Scotland and many sharing those cells have chronic health problems Andrew McLellan Prisons Chief Inspector

His first inquiry criticised living conditions in the jail, where he found slopping out still took place and where there was no running water or electric lighting in cells.

Dr McLellan was also worried that inmates were often locked up for up to 15 hours at a time at weekends.

The new report welcomes the end of cells with no electricity and praises the jail's tidiness, as well as a new unit which provides better living conditions for some inmates.

But Dr McLellan said: "Two serious and urgent concerns were identified in last year's inspection report.

"One was about the condition in which prisoners were living and the other was about the small amount of preparation which long-term sex offenders received prior to their release.

'Potties' sanitation

"These concerns remain, although the installation of electric power in cells has helped improve one part of the bad living conditions."

He added: "Porta-potties provide the only means of sanitation in cells where prisoners may be locked up for 15 hours at a time during weekends.

"There is also no access to running water for hand-washing when prisoners are locked up, and they have little or no say in with whom they may share their cell. "

The watchdog said: "The cells are also among the smallest in Scotland and many sharing those cells have chronic health problems."

Local politicians have been pressing Justice Minister Cathy Jamieson to speed up plans to improve conditions at Peterhead.

She acknowledged the report but argued that the Scottish Executive was "committed to tackling these issues, not just at Peterhead but across the whole prison system".

The executive had given a "clear commitment" to ending slopping out in Scotland and the prison service was spending �1m a week on improving prison conditions.