Image copyright PA Image caption Forty prisons have been told to take in more inmates, although 34 are already full

The government has ordered dozens of already full jails to take more inmates because the jail population is growing faster than expected, it has emerged.

Forty prisons in England and Wales have been told to raise their "operational capacity" in the next two months, according to documents seen by the BBC.

All but six of these are running at full capacity or are overcrowded.

Justice Secretary Chris Grayling said he was taking "sensible steps to make sure we can accommodate everyone".

The prisons affected include Bedford, Durham, Leeds, Leicester, Lincoln and three facilities in London - Brixton, Pentonville and Wandsworth.

'Very difficult'

The jails have been told they need to find accommodation for 440 more prisoners, in total.

This figure represents about 0.5% of the prison population of 85,410. On average, the 40 prisons affected will have to find space for an additional 11 inmates each.

BBC home affairs correspondent Danny Shaw says it will be very difficult for prisons to deal with any increase in inmates.

Several facilities are already at 150-160% capacity, he says. And Wandsworth prison has nearly 1,600 inmates in cells designed to hold about 900.

Image caption More prisoners may be required to share cells originally designed for one

He adds that the order to take in more prisoners is very embarrassing for the Ministry of Justice, which has closed 16 jails in the past four years.

A further two prisons were converted to immigration removal centres, after prison population forecasts suggested numbers would stabilise or rise only slowly.

A quart into a pint pot won't go. This type of environment will do nothing to rehabilitate prisoners Sadiq Khan, Shadow justice secretary

Mr Grayling said he was making "no apology that we are sending more criminals to prison" because "that's what the public want".

He said: "We have had a small increase in [the] prison population in [the] last few months. And as a result we've opened up some of our reserve capacity.

"We're also opening 2,000 additional adult male prison places over [the] next nine months as part of my commitment to ensure we go into [the] next election with more adult male places than we inherited in 2010."

Shadow justice secretary Sadiq Khan said the government should accept that the decision to close prisons had been wrong.

"Because of ministers' incompetence they've created an acute shortage of space.

"Their latest desperate measure is to stuff more and more prisoners into already dangerously overcrowded prison cells. But a quart into a pint pot won't go.

"This type of environment will do nothing to rehabilitate prisoners or to reduce crime."

Twin beds

But prison reform campaigners called on politicians of both sides to "wake up to the damage they are doing".

"Solutions lie not in warehousing more people or exploiting fear of crime but in authoritative leadership to ensure that offenders make amends to victims, break addictions and take responsibility for their lives," said Juliet Lyon from the Prison Reform Trust.

I struggle to recall a time when there were so many issues and problems Eoin McLennan-Murray , Head, Prison Governors Association

And the Prison Officers Association described the development as a "fiasco".

It said emergency measures were also being put in place to recruit staff after thousands of prison officers took voluntary redundancy.

Retired officers and those who have recently left the service are being offered short-term contracts to re-join until the end of the year.

President of the Prison Governors Association Eoin McLennan-Murray said he had been told to find space for an extra six prisoners at Surrey's Coldingley Prison, where he is governor, which he was doing by putting extra beds in cells designed for two people.

Other jails are likely to fit twin beds in single cells.

'Perfect storm'

Mr McLennan-Murray, speaking on behalf of the PGA, said the prison population was now expected to rise by 1,000 more than earlier projections.

"All the planning assumptions are based on smaller population projections."

Speaking in his capacity as head of the association, he said this issue combined with prison staff shortages, a new prison regime and increasing numbers of assaults and incidents, was creating a "perfect storm".

"All of these things will de-stabilise prisons," he said.

"I struggle to recall a time when there were so many issues and problems."