The waiting room is small and the only other person in it is a small child. A family group appears from the bottom of a staircase and reclaims the child. The sergeant-major signals and I advance to an airlock system of sliding doors. They close behind me.

Once inside, low buildings form geometric shapes around well-tended gardens. The architecture is modern, red brick, but the windows are small and the doors heavy. Walking along the covered walkways or up the wing staircases, the unmistakable scents of tobacco and marijuana waft out, mixed with sweat and testosterone. There is a lot of loud music, raised voices and laughter - all types of laughter from real crack-you-up giggles to harshly sarcastic guffaws. Energy and inertia blend. There are 480 men here at Her Majesty’s pleasure.

In the lush green Hertfordshire countryside, with wooded hills and middle-class villages all around, is HMP The Mount, a “category C” prison intended for inmates who would not pose a serious danger to the public if they escaped. But pressures on space can mean that other category prisoners are held here and, at the end of last year, in one of a series of well-publicised jailbreaks and prison riots, three inmates did escape and were recaptured.

The Mount is a training prison, with all inmates required to spend a number of hours a day out of their cells. Their pay, between Pounds 6 and Pounds 10 a week, is earned by working - producing double-glazing, growing vegetables in the grounds, working in the kitchens or by attending the education department.

About 100 at any one time are engaged in education, ranging from basic literacy to Open University degrees. The education service is supplied, for the most part, by Amersham and Wycombe College and its most popular subjects are music, French, Spanish and business studies. Some of the Open University courses call for outside tutors, which the college provides.

There are other people who want to learn in prison, people who may not want to take GCSEs, but who have an imaginative world to develop and ideas and feelings to express. They respond to a figure not part of the establishment nor the college, someone who can go on the wings - as the teachers rarely do - and who can open up another kind of life outside the prison - as the officers cannot. Someone who can, in the words of assistant governor, Steve Metcalfe, “draw out talent that is scarcely visible”. At HMP The Mount, that person has been the writer-in-residence, Jeremy Gavron.

Around 30 or so writers in prison schemes have been jointly funded by the Arts Council and the Home Office since 1992, with the writers receiving Pounds 10,000 a year for two-and-a-half days a week. The Mount scheme is so far the only one where funding has been wholly taken over by the prison authorities.

Jeremy Gavron was one of 270 applicants. Once a correspondent for The TES and Daily Telegraph, Mr Gavron is the author of two books (Darkness in Eden and The Last Elephant) and is currently working on a third. He was interested in teaching and “wanted to stop being a vulture” on other people’s lives. As well as being a confident, articulate writer, he has the right kind of direct, intense and funny personality to cope with prison life.

No bullshit and lots of laughs is the preferred prison way. You ain’t seen macho till you’ve cruised a prison corridor. Yet at the same time, talk to any man individually and the terrible pain of confinement visibly flares out. So, as one educational manager within the prison service put it, choosing writers-in-residence must include no do-gooders, no therapy-types, no one not seriously published and no one more teacher than writer.

“I didn’t know what to expect,” says Jeremy Gavron. “All the residencies rely on a creative meeting between the writer and whoever surfaces in prison. It depends who you meet.” Arts Council guidelines - put on a play, produce an anthology of writing, be a mentor for one-to-one development of writing - provided the sketchiest of outlines for the prison experience and adding to the difficulties of building up a writing relationship was the problem of prisoners moving on, besetting the work with a kind of chronic uncertainty.

The Mount is quite a popular nick. It is not too far from London, so visits are not too bad for most of its prisoners’ families. It was built originally as a young offenders’ institution, so looks less forbidding than many others. Its governor, Mrs Margaret Donnelly, in charge since 1991, believes sincerely in education and the arts. The Mount has television in the cells (rather to the despair of the prison librarian) and under Mrs Donnelly’s reforming regime there will be three tiers of privilege, which must be earned by good behaviour. The working week will be raised from 27 hours a week to 32; additional visiting time allowed; prisoners will be allowed out of their cells to eat together; there will be additional association (leisure) outside working hours.

And there are already some sports teams, craft activities and drama events, as well as pre-release training groups and family support counselling groups.

It’s all designed to re-socialise men who, as Mr Metcalfe says, “are often very inadequate. A lot of them just don’t know what to do with their lives. Of course,” he adds hastily, “some are real hard nuts who don’t give a toss and want you to know it - and for some it’s just a way of life. But some are under-achievers who use threats or violence to impress others. If they find they are good at something, they can behave better because they feel proud of something.”

When Jeremy Gavron first went to The Mount he put up a notice saying “writer-in-residence” and sat under it in the corridor which runs to the canteen. Here men made appointments to discuss everything from a 300-page manuscript to love letters home.

For a few months Jeremy tried “to get ‘true confessions’ - you know, write about your own experiences, they are so interesting”. But just as the men do not borrow crime stories from the library (they like practical reference books and science fiction), they would rather get away from their own lives in their writing, too.

He ran a writing competition. There were 12 entries, all poems and stories; so he held a popular poetry reading where five men read out their work. But competition discouraged the losers. Next, a musical play called Crack got a mixed reception. The Jamaicans didn’t like their culture being talked about and possibly “dissed” (disrespected) by outsiders. Then the weekly Thursday evening writing workshops became established, leading to the publication of an anthology, From the Pen. A writing community was established in the prison, with Jeremy Gavron offering “encouragement, cajoling, editing, someone to talk to”. From that anthology developed the regular publishing of a prisoners’ magazine, XMT.

The first edition of the magazine, published at the beginning of last year, was produced in the face of “enormous inertia”, Jeremy Gavron says - to the extent that he had to type the whole edition himself on his home computer. Now XMT is produced on an Apple Mac provided by the Home Office, and Jeremy Gavron has been replaced by the inmates. The men who produce the magazine are proficient in desktop publishing and know all about the merits of different graphics packages. They’re involved in production, distribution and marketing: they’ve changed the paper size, helped to get a machine for collating and stapling and now try to sell enough copies (price Pounds 1) to cover costs.

Andy Chaplin, the editor, was a travel agent who got involved in a fight and killed someone. He went to public school and a German university. He has the confidence to organise and has faith in life outside. “There’s nothing worse than not being able to walk out that gate,” he says, talking about his family.

Darin Harwood, co-editor, is tall and blond and handsome, went to college in South Africa and then joined the army. He’s done “lots of crime”, including smuggling arms and robbery but says “coming into prison really does open your eyes”. For him, “writing is something you can do on your own”. Andy Chaplin concurs. “It fills enormous amounts of time. The great thing in prison is to avoid boredom.” Both of them have written huge, complex thrillers.

XMT is full of sardonic wit. As well as humour and agony columns, serious interviews with the governor or prison officers, surveys of prisoners and officers, comments on the national news, crosswords and quizzes, there is also fiction and poetry. It is, says Steve Metcalfe, “an excellent forum for inmates and staff”. Editorial policy is “no whingeing”: complaints about the prison must either be as vox pops in interviews or as satire.

Some of the best articles are surprising: Pip Manson recalls old schoolfriend Jerry Rawlings, president of Ghana; Roland Barrett shares his experience of a Thai jail; Troy Chin makes a powerful plea to end gun law in Jamaica. Others are more predictable: “so there was the dog chewing off my arm”. Poetry is generally romantic or comic.

Paul Ruddock was a tube-driver who is doing time for dealing drugs. A slight man with bright blue eyes, he is studying for an A-level in psychology and passes the time by reading and drawing, and writing thrillers on his PC. He first got involved in the magazine by writing an article on writing an article. Now he regularly does cartoons as well as updating readers on the soaps.

Troy Chin comes from Jamaica and will be deported when his sentence for drug-smuggling ends. He has a pigtail, cooks his own “health food” and misses “love at nights”. He was writing a book about posses (Jamaican gangs) but has given it up. Just at the moment he is in a lot of trouble on his spur (corridor) because of his article decrying the violence in Kingston. They say he has dissed Jamaica.

Tempers can run high in prison, even with a lot of cannabis slowing most of the heaviest people down; that’s why, rumour has it, prison officers go easy on it. When Hector Harvey wrote a spoof life of an informer in XMT he got into a lot of trouble from people who didn’t see the joke - “we don’t like squealing”. Troy is lying low for a bit. His next contribution is going to be a love story from outer space. “I was expectin’ a bit of gravellin’ but it goin’ on and on,” he complains to Jeremy as we sit in the bleak television room on his wing. What he’d really like to write about is the criminal justice system, but outer space is safer.

Troy is cheerful, Paul is resigned, Andy and Darin are determined. They and many others will remember Jeremy Gavron. But it’s not all laughs at The Mount. As Steve Metcalfe says: “He’s made a dramatic difference to a few lives, let’s not make him out to be Superman.”

Here’s a story Jeremy tells. Grant Clare had been a junkie since he was 14. He started to write poetry in prison and said the fog in his mind had begun to roll away. He wanted to go to a rehabilitation centre but was released early on parole, without rehabilitation. “If I died now it wouldn’t matter, I’ve actually done something with my poetry,” he said to Jeremy before he left. He died of an overdose within a week.