Prisoners are being locked up in their cells for too long each day at a Sussex jail.

That is the verdict from inspectors after the Independent Monitoring Board’s annual report into HMP Lewes found a number of shortcomings at the prison.

These included poor food hygiene, a 45% rise in discrimination incidents, a continuation of drug misuse, and healthcare complaints doubling in a year.

But the main concern to come out of the report was the 40% of prisoners found to be locked in their cells during the day when they should be in education or working.

Jenny Blackburn, chairwoman of the Independent Monitoring Board at HMP Lewes, said: “Prisoners cannot prepare themselves for a law-abiding future by doing nothing all day.

“The board reports a worsening situation in the past year, despite all the efforts by staff.”

There is a maximum of 375 activity places available for the 660 prisoners, and with a high rate of staff sickness, activities are often cancelled and prisoners shut in their cells, the inspectors found. These unplanned lockdowns are now three times as frequent as this time last year.

But even when the activities are offered, the attendance rate of 70% remains low, the inspectors said.

Due to overcrowding, some small cells with in-cell toilets which are designed for one prisoner are being shared by two inmates.

The report said: “The two prisoners are still in effect sleeping, eating and living in a large lavatory.

“These conditions are uncivilised, and the IMB deplores them.”

Poor hygiene in the kitchen has been a concern for the board as they are not convinced the 30 prisoners employed there wash their hands before preparing food.

There was a sharp increase in discrimination incidents – nearly doubling in a year.

And the IMB was curious that most complaints were from staff about prisoners rather than from prisoners about staff.

Deaths in custody halved to two from the previous year. There are two deaths from July 2012 which have yet to be heard at an inquest.

Among the other issues brought up in the report were the prisoners complaining about food portions, the change from green to white towels and linen leading to more staining, healthcare complaints taking up to 20 days to be dealt with and the concern over the wide use of cannabis in the prison.