The prison population in England and Wales reached a record high today with more than 85,000 people held in custody.
Ministry of Justice statistics confirmed the total had reached 85,076, a rise of almost 3% on the 82,773 held 12 months ago.
The number showed an increase of 192 more inmates in just one week, bringing prisons closer to their current capacity of 87,196 spaces.
In February Justice Secretary Jack Straw announced the end of an early release scheme which has seen more than 80,000 offenders let out.
No prisoners were eligible for the controversial End of Custody Licence (ECL) scheme after March 12 and the last remaining ECL prisoners were out on April 9.
The new figures heightened fears that new measures will be needed to relieve pressures on the prison estate after the General Election.
And it provoked immediate criticism from campaigners who called on every political party to address an overcrowding crisis.
Juliet Lyon, director of the Prison Reform Trust, said a new Government must take a second look at the system.
She said: "With a government of any stripe facing tough choices after the election, the cost of sustaining our out-of-control prison population has gone beyond affordable bounds.
"Instead of planning how to cope with ever-rising prison numbers, politicians should be working hard to reduce any unnecessary use of imprisonment.
"This would mean less breach and remand, fewer mandatory terms, a review of indeterminate sentences and proportionate sentencing guidelines."
Frances Crook, of the Howard League for Penal Reform, said leaders of all political parties must set out their policies to tackle a crisis in prisons.
She said: "This ceaseless growth in prison numbers is untenable and any new administration will have to bite the bullet and find a strategic way to reduce the prison population."
A Ministry of Justice spokesman confirmed the total prison population today was 85,076 and usable operational capacity was 87,196.