You find the Michael Palin Centre for Stammering Children (a title that can't help but have a Pythonesque air to it) above a shabby, unloved health centre off Farringdon Road.

The dingy stairwell and peeling paint belie its international reputation for treating children with the most extreme and intractable kinds of stammering.

And like many of London's small, unsung centres of medical excellence, for several years it has existed in a state of near-constant financial uncertainty.

Yet a chance meeting in a TV green room between Palin and Secretary of State for Children Ed Balls, who himself used to stammer as a child and still has a slight disfluency, this summer ensured the continuing survival of the centre, which is funded partly by the NHS and partly by charity. It's a good news story that deserves wider recognition, for the work carried out here is profoundly changing the lives of hundreds of disabled children in London and across the country.

“We were both visiting ITV studios on the South Bank and, as one does, happened to meet up afterwards,” says Palin, the comic actor and TV traveller. “Actually, he collared me and said he was very interested in the work of the centre. We talked for a while, and he said he'd had a stammer but had got over it.”

As a result of that collaring, in July the centre was given a £340,000 grant by the Department of Schools, Children and Families to implement an education programme in schools (“There are still teachers who don't understand stammering, who get a bit cross and tell stammerers to spit it out',” says speech and language therapist Willie Botterill, shaking her head). The sum effectively guarantees its work for at least the next few years.

It was in 1993 that Palin helped to set up the centre, in tribute to his father Edward, whose severe stammer emerged when he was a child and which he never truly overcame. Palin Snr was a stoic man, a manager in a steel works in Sheffield who shared his son's healthy sense of humour. Yet the stammer tested his “generally mellow sort of temperament” to the limit and could not help but affect the whole family.

“He could be quite the lad in the right situation and I think was actually rather a light-hearted man,” says Palin. “But he could also get very cantankerous, and sort of irascible with himself and with others because he couldn't communicate.
“I think it must have been extremely difficult for him at work to participate in quite the same way that everyone else did. The feeling I get is that he was probably passed over for promotion because of his stammer.

“If you think about it, it must be one of the worst things of all, really — knowing exactly what you want to say but not being able to say it.”

In Edward Palin's day, stammering was often perceived as the stammerer's fault, as though it were some sort of character flaw. Children were even punished for stammering.

“My mother told me this wonderful story, that he stammered because a maid jumped out on him at his home when he was little, which conjures up all sorts of dark thoughts and imaginings,” laughs Palin. “But I don't think for a minute they were very progressive in dealing with it. I'm sure it was seen as an affliction rather than something that could possibly be treated.”

Indeed, as far as Palin knows, his father was never given any form of therapy, if such a thing even existed. Yet there's great pathos in Edward Palin's attempts to treat himself: “After his death I was clearing out some bookshelves,” says Michael, “and came across quite a lot of books he must have used in the Twenties and Thirties on relaxation techniques. I think that was his attempt to deal with it.”

Though stammering isn't helped by anxiety, it's now thought that the condition is the result of physiological developmental problems, which occur at a very early age.

“The neural pathways don't develop in exactly the way they should,” says Botterill, “and that sets up a problem which is then impacted by genetics, environment, linguistics and, to an extent, temperament. It's actually a complex problem, which is why it's so important that we see children right from the moment they start
to speak.”

Stammering, like all speech problems, affects more boys than girls. “Interestingly, the ratio is about the same when they're very little but many more girls recover from it at a later age than do boys. We don't really know why.”

There is a strong genetic component, and more than half the children seen at the Michael Palin Centre have parents who stammer, or used to stammer. Despite his dad's severe problem, Palin himself, however, has never been a sufferer: “And neither has my sister, which is interesting, and lucky, because both of us felt the direction we wanted to take was into acting. Though I have heard of actors who can perform perfectly well on-stage, speaking someone else's words, and yet who stammer when they're being themselves.”

The comedian Rowan Atkinson, famous for the silent Mr Bean, has admitted stammering, and so has the pop singer Gareth Gates. The arts world's elder statesman, Jonathan Miller, used to end up at the wrong destination on the bus, since he'd ask for a ticket to wherever was easiest for him to say at the point he boarded. And Margaret Drabble has confessed that her stammering turned her into a walking thesaurus. Finding herself unable to say a particular word, she'd quickly search for the nearest synonym and use that instead.

Yet it would be wrong to under-­estimate stammering as a disability. Children with problems that local therapists can't solve are referred to the Michael Palin Centre from across the country, and sometimes arrive with barely comprehensible speech.

On the day I visit, I meet a bright, confident 19-year-old called Kieran, from Peckham, who came to the centre with not only a severe stammer but also with a speech problem called “cluttering”, where words and syllables are incoherently bunched and rushed together.

After therapy, people are now able to understand him well enough — but he is off to art school anyway, where he can fully indulge his love of non-­verbal expression.

People will go to great lengths to attend the centre's two-week intensive courses: one family from Cumbria, unable to afford the price of a London hotel, stayed at a campsite in Essex; another from South Wales brought their caravan and negotiated a rate with Sainsbury's at Angel to stay for a week in the supermarket's car park.

“Parents are key players until a child is about 14 or 15 and we involve them all the way in both assessment and treatment,” says Botterill. “I think parents find it hard to parent children who stammer in the same way they parent their other children. Perhaps, for example, they learn that when they tell the child off, they stammer more, and so they stop telling them off — and then all hell breaks loose with that child. It's important that parents treat all their children the same way and we help to give them the confidence to do that.”

Yet there is no quick fix for stammerers — and no cure. Children are taught long-term techniques to manage their problem but sometimes feel that the mental effort required to become perfectly fluent robs them of some other part of their personality.

“It's a bit like learning a new language. To become pretty much fluent, you have to concentrate very hard and think about it all the time. Though it gets better with time, some people have developmental systems that make it extremely difficult to master. It can come at considerable cost to spontaneity.”

Michael Palin, of course, employed a stammer to great comic effect in Ken Pile, the brilliantly bungling hitman in A Fish Called Wanda, a film that's now 20 years old. John Cleese, who wrote it, asked Palin to take the part because of his experience of the condition, but: “I wouldn't have done it had my father still been alive then, oh no. That would have been very difficult indeed.

“I do think we've got to realise that lots of people stammer,” continues Palin, “often people who are very bright and very brilliant and who have lots to say. There's no point hiding them away or pretending it doesn't happen. You're obviously not incompetent at life if you stammer, and the more we see of them, the more we hear of them, the better adjusted we all will be.” He laughs. “That's my defence of Ken, if you like …
“In this very rushed, very busy sort of world, where you often have to give account of yourself very very quickly, I do think it's important that we realise how hard some people might find some situations — and, clearly, that we find good ways to help them.”