LONDON - Overcrowded Victorian inner-city jails are under threat from prison reformers on all sides of the political spectrum who want to demolish and rebuild them.

This week the Conservatives joined the fray when the party's Justice Spokesman Nick Herbert called for a redevelopment of the prison estate in England and Wales.

"We need a fundamental redesign of prisons to try and reverse the reconviction rates which have soared under Labour," Herbert told Reuters.

Some 65 percent of prisoners now reappear in court after release, compared with 57 percent in 1998, according to Home Office figures quoted by the Conservatives.

"Prison in its current form is not working," Herbert said. "The regimes are deeply unsatisfactory and there is insufficient attention to rehabilitation and purposeful activity."

At the root of the current problem is the lack of space in prisons -- inmates have risen by a third in a decade, with 17,000 prisoners now forced to double-up in cells.

"The prisoner movements which that requires, the stretch on staff which that produces, make rehabilitation impossible," Herbert said.

He wants to replace aging prisons with a network of small jails -- in contrast to previous official recommendations which envisaged a series of regional super-sized prisons each holding around 1,500 inmates.

"There is huge merit in smaller local prisons, which would mean that offenders can be close to the communities from which they come, and their families will aid rehabilitation and resettlement," Herbert said.

The proposal echoes the recommendations of a report from Labour peer Baroness Corston, which called for the closure of all women's jails and their replacement by a small number of custodial units for only the most dangerous female inmates.

Justice Secretary Jack Straw is due to respond to Corston's proposals shortly, probably at the same time he publishes a report from government trouble-shooter Lord Carter on prison overcrowding.

It was Carter who proposed the idea of replacing aging jails with regional "superprisons" in a report for the Home Office five years ago.

But Herbert said large "community" jails would be a mistake, and not just for policy reasons.

"It will be easier to secure land and planning agreement for a number of smaller units than for big superprisons," he said.

Herbert says the government is reaping the consequences of ignoring for too long the problem of rising prisoner numbers.

The government plans to add an extra 9,500 prison places by 2012, but even that will be too few, based on Home Office projections for the rise in the prison population, according to Herbert.

He said the government was instead planning to solve the crisis by cutting the numbers going to prison and increasing the use of community sentences -- an approach he condemned.

"There is an existing demand from the courts to sentence offenders who are repeat, violent or serious offenders," Herbert said.

"And there is a demand to deal with those crimes from our society, in particular violent crime, and that requires us to incarcerate them."

Straw said last week he agreed with the Lord Chief Justice, Lord Phillips, who said that "some method must be found of linking resources to the setting of the sentencing framework."

What that means, said Herbert, is that if prisons are full, some offenders will be given a non-custodial sentence instead.

"The way to deal with the growth in the prison population is to deal with the reconviction rate," he added.

"The wrong way is to try and manage the prison population downwards by pushing people who should be incarcerated out into weak community sentences."

Herbert said the current prison population was largely made up of serious, violent or repeat offenders for whom non-custodial penalties were inappropriate, leaving little scope for cutting prisoner numbers.

"They have usually gone through the gamut of community penalties which have failed and have been imprisoned as a last resort."