The prison population in England and Wales has reached a record high.
The total number of prisoners hit 85,578 on Friday - 83 more than the previous record of 85,495 set last October and just under 2,500 short of the usable operational capacity of 88,073, Ministry of Justice figures show.
Criminal justice campaigners have called on the Government to reduce the number of people behind bars.
But last month Prime Minister David Cameron scrapped Justice Secretary Kenneth Clarke's "too lenient" plans to let offenders who plead guilty out of jail early.
Mr Clarke had proposed increasing the discount for the earliest guilty pleas from one third to a half in a bid to encourage more offenders to admit their crimes, saving costs and sparing victims the ordeal of a trial, but Mr Cameron forced him into an embarrassing U-turn after the plans came under fire from the Tory right and victims of crime.
A Ministry of Justice spokesman said: "We will always ensure there are sufficient prison places for offenders sentenced to custody by courts.
"There is currently a substantial margin between our available capacity and the actual population. New accommodation continues to become available and in the next 12 months 2,500 new places will become operational."
Frances Crook, director of the Howard League for Penal Reform, said: "Every week we cram hundreds more people into our already bulging jails, only for people to leave prison unchanged and to go back to crime. Prisons are awash with drugs, violence and arson and this is inflicted on local communities when people leave prison.
The answer to rising prison populations is not to build more failing jails. This ceaseless growth in prison numbers is untenable and I implore the Government to bite the bullet and find a strategic way to reduce the prison population by putting an end to short-term prison sentences.
"A record prison high is a sign of failure, not success."