“It is essential that staff and prisoners are safe in the prison.
“I urge management to engage with the union so that all who live and work at Wormwood Scrubs are safe from violent attacks.
“Management and Government cannot continue to turn a blind eye to the drug culture which is making our prisons unsafe.”
A report by Peter Clarke, the chief inspector of prisons, found last month that Wormwood Scrubs suffered from squalid conditions and the number of assaults on inmates and staff was double the level of comparable institutions.
Some prisoners told inspectors they were too frightened to leave their cells.