It used to be sewing mail bags, picking oakum and working the treadmill, now the government has come up with a wheeze to get convicts busy with sandbags, fence posts and kit for the armed forces. The Justice Secretary, Chris Grayling, says the ten-year deal will teach convicts ‘the value of a hard day’s work’.

This has been tried for six months with Coldingley prison in Surrey and Grayling reports savings of nearly £500,000. Although that figure must be offset by the £72,000 of taxpayers’ money he has just spent trying to overturn a court ruling against his ban on inmates receiving books from visitors. He is also planning major reforms on rehabilitation of offenders.

‘For too long we have released prisoners back onto the streets with £46 in their pockets and little else other than the hope that they would sort themselves out,’ he says. ‘Now all this will change. For the first time we will be giving all offenders a proper chance at rehabilitation, instead of just leaving them to wander the streets and get on with it.’

Anyone who has watched the destruction of our penal institutions over the past two years may wonder what happened to the idea of prison as a place of rehabilitation. What kind of men are now being released? When I taught in Wormwood Scrubs in 2007, it kept 1,355 men confined in a place built for 860. It was chronically underfunded even then.

But I first realised how good it was when we were visited in the art room by some redoubtable prison reformers from New Jersey. They gazed in wonder at a lot of messy acrylic paint tubes and wizened old brushes. The sinks were filthy and a group of Afro-Caribbean inmates hid behind tents made out of bedsheets and easels, smoking spliffs, listening to rap music and talking patois. To me it looked like a pit, but to the pious American ladies it was a revelation. They had seen nothing like it back home.

Once I’d got used to prison culture, with the constant intrusion of security, I found the Scrubs quite a cosy place. For many inmates it was the nearest thing to home they’d ever had. It was dirty, the food was lousy, the medical facilities were almost nil, but the men made friends and made the best of it. Many came up to education classes; these were full and had a waiting list to get in. Some men took an interest in art for the first time, while radical Muslims who couldn’t look at human images enjoyed the work of flower painters such as Henri Fantin-Latour.

As we enjoyed our coffee and biscuits together, smuggled in by me, I used to fantasise about taking a party to the National Gallery or the National Theatre. I felt I could reach them through cultural experiences they hadn’t had before. My other classes in English and history were great fun, although the foreign men, particularly the Africans, always outshone the British lads, who had had the worst education.

Britons often have a false picture of prison life from watching American films, which dwell on the terrible cult of prisoner rape, but there was none of that in the Scrubs and I didn’t hear of it in other UK prisons. Perhaps that was because 32 per cent of inmates in the Scrubs were Caribbean and tended to be homophobic. When I made a request for Peter Tatchell to give a talk, the governor refused, saying it would ‘cause a riot’.

I didn’t hear about much bullying, though men got beaten for stealing from each other. The people I met in my classes were happy enough and some thrived. Boys who’d grown up in care appreciated the order and routine. Jokes were currency and I hadn’t laughed so much since I was in school.

My prison experience reminded me of Porridge, the old TV sitcom, and films such as Two-Way Stretch. But the peaceful, rather indolent prison I knew has gone. Over the past two years the Scrubs, always a well of need, has changed into a pit of despair, from an establishment described by inspectors as getting the basics right to a hole where five men died last year. As many as six people a month are now killing themselves in our prisons.

The place where I worked was doing well on tight rations, but now it has been left to starve. Prison governors have been ordered by Grayling’s department to make savings of £150 million a year. A recent spending review saw a further 10 per cent reduction in the Ministry of Justice’s budget. The most damaging effect of this has been to drastically cut the number of prison officers.

In the Scrubs, there are wings containing 300 men controlled by nine junior officers. Many senior staff have been made redundant or have left due to stress. There is increasing violence between staff and prisoners, as well as between prisoners, who now spend all day banged up in their badly ventilated cells. Attendance at classes has dropped and many workshops, the key places for rehabilitation, have closed.

‘I’m absolutely clear, there is not a crisis in our prisons,’ Grayling declared last year, at the same time as the Isis Young Offenders Institution in London was criticised in an official report for the high levels of violence there, often involving weapons. Official figures from the Ministry of Justice showed that the number of assaults by prisoners in England and Wales rose to more than 15,000 in 2013–14, from around 14,000 the year before. The latest statistics also reveal a record number of serious assaults, including attacks by prisoners on staff.

Danny Kruger, who runs the crime-prevention charity ‘Only Connect’, says his work has become almost impossible since government cuts. ‘We deliver some education services in London prisons,’ he says. ‘To do our work we need prison officers to unlock and escort the inmates to the classroom. If we’re lucky we get half a class, maybe six prisoners; if we’re not, we get none. This is what budget cuts and poor morale does to a system that never worked well in the first place.’

Prisons inspector Nick Hardwick, who published a report on the Scrubs last November, said: ‘Major structural changes in late 2013 had led to a significant reduction of resources. We were told that one consequence of this was that a large tranche of experienced staff had left very quickly and that this had been destabilising, not least because the prison had found it difficult to recruit replacements. This inspection found that the prison had declined significantly in almost every aspect.’

‘Wormwood Scrubs has been through a difficult change process,’ says Michael Spurr, chief executive of the National Offender Management Service. ‘It has had to adapt to hold young offenders alongside its adult population while implementing new structures and routines to provide a decent regime for prisoners at a lower cost. This has not been an easy transition.’

It’s been impossible. Our prisons are going the American way, without the hygiene. Nelson Mandela once said, ‘No one truly knows a nation until one has been inside its jails.’ Grayling’s empty pronouncements suggest that all this nation really cares about now is getting hold of ready cash.