The Chief Inspector of prisons Nick Hardwick has issued a stark warning on the state of prisons in Wales and England.
It comes after the UK Government admitted more prisoners would have to share cells to cope with an unexpected rise in numbers.
Mr Hardwick said cuts had left the prison system so stretched that more inmates were killing themselves, or getting deliberately sent to punishment blocks to escape crowded conditions.
Justice Secretary Chris Grayling rejected the criticisms, insisting the number of assaults and cases of self-harm were falling, and that 2,000 extra prison places were being built.
Swansea is currently the most overcrowded prison in the UK.
According to the latest figures it currently holds 455 inmates, 184% more than it's uncrowded capacity of 242.