The first signs of a jump in the prison population following last week's disorder are emerging, as analysis suggests rioters are getting sentences 25% tougher than usual.
Official figures from the Ministry of Justice confirmed the total prison population in England and Wales had reached 86,654, leaving a 'useable operational capacity' of just 1,439 spare places.
That compared to a total population of 85,931 one week earlier.
Unlike most Augusts, when the prison population usually does not rise, the criminal justice system's bid to respond forcefully to the violence seen in London, Birmingham, Manchester and elsewhere is piling huge pressure on the system.
"This is causing massive problems for prisons," Harry Fletcher of probation officers' union Napo told the Guardian.
"There are so many of them coming through the system, it is causing considerable problems. When people are being held so far from home it causes real difficulties for their families."
Analysis by the newspaper suggested convicted rioters were being given prison sentences roughly a quarter longer than usual.
Those charged with theft or handling stolen goods received an average of 5.1 months.
Most surprisingly, 70% of defendants appearing before magistrates were sentenced to prison terms - compared to just two per cent in usual circumstances. It follows prime minister David Cameron's call for all convicted rioters to go to prison.
That leaves the prison population creaking, many now fear, but MoJ officials insisted spaces in young offender institutions would be able to take up much of the extra strain.
"There is substantial capacity in the prison system," a spokesperson said.
"We will provide prison places for those committed to custody by the courts."
Contingency plans are being developed, however. So far nearly 1,300 people have appeared before magistrates on charges relating to the riots, of which nearly 800 have been remanded in custody.