UK prison population on 25 December will be 400 above last year's figure and at an all-time high

More people than ever before will spend Christmas behind bars this year, figures showed on Friday.

A total of 87,393 people are in jails in England and Wales, 567 fewer than last week but almost 4,000 more than there were a year ago, according to Prison Service figures.

The announcement came as campaigners warned that the current prison population was "neither justifiable or sustainable".

Juliet Lyon, director of the Prison Reform Trust, said: "Unless government can succeed in reserving prison for serious and violent offenders, the cost to the taxpayer will rocket in 2012.

"Meanwhile, very many people are behind bars who should be taking responsibility for themselves and looking after their families, doing unpaid work or making amends to victims and, in many cases, engaging in treatment for drug or alcohol abuse or getting the mental healthcare they need."

The prison population hit an all-time high of 88,179 in early December but the new figures are the highest ever for the Christmas period.

Last Christmas there were 83,701 prisoners; in 2009 there were 84,231; in 2008 there were 82,918; in 2007 there were 80,707; and in 2006 there were 79,627.

The jail population had never exceeded 87,214 before September this year.

A Prison Service spokesman said: "We have seen a significant rise in the prison population since the summer, with very strong rises following the public disorder.

"Managing the increase ? is challenging but we have been continually developing contingencies to manage the additional population.

"We currently have enough prison places for those being remanded and sentenced to custody.

"Capacity will continue to increase throughout 2012, with the opening of two new prisons.

"We will continue to explore contingency arrangements should further pressure be placed on the prison estate."