The prison population in England and Wales has reached a record high.
The total reached 85,368 - 167 more than the previous record of 85,201 reached on May 21, figures released by the Ministry of Justice show.
The usable operational capacity was 87,628, the figures also reveal.
Justice Secretary Kenneth Clarke plans to reform sentencing and penalties, saying the prison population is too high and that there should be greater emphasis on rehabilitation and community sentences.
A Prison Service spokesman said: "The total prison population on Friday September 24 2010 was 85,368, of which 0 prisoners were held overnight under Operation Safeguard. This is 176 more than last Friday, when the total was 85,192.
"Usable operational capacity on September 24 was 87,628. In addition, Operation Safeguard remains in place and can provide up to 400 places."
The prison population, which consists of 81,086 men and 4,282 women, is almost 1,000 more than the corresponding Friday 12 months ago when the total was 84,382, the Ministry of Justice said.
The figure is also more than 14% higher than six years ago, figures for previous years showed. The total stood at 74,606 on the corresponding Friday in September 2004, 77,291 in 2005, 79,642 in 2006, 81,133 in 2007 and 83,508 in 2008.
Jon Collins, campaign director for the Criminal Justice Alliance which represents 48 organisations, said the figures are a warning for the Government that they must act urgently to reduce the number of people in prison. He said: "There isn't the money available for the Government to try and build their way out of this prisons crisis.
"Two decades of mismanagement of the criminal justice system have resulted in a huge and unsustainable prison population. Unless action is taken to reduce the number of people in custody, the prison system will be simply unable to cope."
