Governors warn of prison time bomb as inmate numbers hit record levels

Hundreds of rioters are being "warehoused" in England's jails, pushing the prison population to record levels and increasing the risk of internal disturbances, violence and reoffending, the Government was warned yesterday by its own prison governors and officers.

Insiders spoke of the strain placed on the system by the riots, painting a portrait of a service buckling under the increase in inmates – in contrast to public reassurances from the Ministry of Justice (MoJ).

Prison officers gave warning that the overcrowding has already led to heightened tensions, and that reoffending will rise because rehabilitation services have been compromised. A leaked memo to prison governors from the MoJ showed that there are concerns in Whitehall about the safety of rioters being held on remand. Three new arrivals were attacked at Cookham Wood Young Offenders Institution in Kent, it was revealed.

The number of prisoners yesterday hit a new record of 86,654 – up 723 on the previous high set last Friday, and leaving fewer than 1,500 spaces in the system. The four major remand prisons in London – Wormwood Scrubs, Wandsworth, Pentonville and Brixton – are under particular pressure.

Paul McDowell, the governor of Brixton Prison until 2009 who is now chief executive of the crime-reduction charity Nacro, said: "What we've seen over the past week is huge numbers of people being sent to our inner-city prisons which are already struggling to deliver rehabilitation services to inmates.

"Many of those being put behind bars will spend three to four months in the cells with no constructive activity whatsoever. I wouldn't be surprised if the re-offending rate increases," he added.

Steve Gillan, General Secretary of the Prison Officers Association, said: "We are dealing with the most over-crowded prison network that we can ever remember. It is simply unsustainable if we continue at the rate we are going."

The Prison Service said it was facing an "unprecedented situation" but insisted that it was "developing contingencies to increase usable capacity". This could include Operation Safeguard which involves using police cells to house prisoners in the short term as well as re-opening facilities which have been closed down in recent months.

Immigration Minister Damian Green also said the Government wanted to deport any foreigners convicted for taking part in the riots.

Eoin McLennan-Murray, president of the Prison Governors' Association, said: "If the courts continue to be heavy-handed with other offences ... that would be problematic longer term."