Dame Margot Fonteyn positively floated through the castle on her way to awarding me my degree at Durham University. Bill Bryson, who steps into the late prima ballerina’s old pumps as the university’s new chancellor, might trundle by with a little less grace. Still, it is remarkable how Bryson has pirouetted his way into our national affections.

Not only has the American travel writer, celebrated for his hilarious send-ups of frightful British seaside landladies, seduced us into buying warehouse-loads of his books; our elite has clasped him to its generous bosom. As well as lumbering around in a gown at one of our older, and stuffier, universities (in direct succession to another grand card, the late Sir Peter Ustinov), he has also become a commissioner at English Heritage.

Bryson even became embroiled in the Kimberly Quinn/David Blunkett grudge match when Quinn gave him the number of a senior Home Office official as Bryson tried to keep his American daughter-in-law in Britain. Hell, you can’t get more Establishment than a passport scandal.

It is all quite a transformation for one whose nose seemed forever pressed against the dirty window from outside, watching two old trouts munching Spam sarnies. Now his milieu will be more rarefied, befitting one who resembles a faintly shambolic don.

The marriage between Britain and Bryson is like the tempestuous union between Blair and Brown, or George and Mildred. As with the squabbling Labour duo, Bryson is going through one of his periodic love-ins (there is, he concedes ruefully, nothing like returning to America for a couple of years to make him appreciate his adopted home). Britain is, he contends, enjoying “a new golden age”. Only his robust views on education might frighten the natives.

The author of Notes from a Small Island tells me that, contrary to earlier assurances, he is to apply for British citizenship after three decades of alien status here (his application is sure to be less problematic than his daughter-in-law’s, whom Blunkett refused to help). He also delivers, in the vaults of St Martin-in-the-Fields, an impassioned sermon on why Britons should learn to love the old country more; the magnificent old church in London’s Trafalgar Square is a shaming example of our neglect, and Bryson is here drumming up support for a £34m makeover. An exhibition about the project, At the Heart: the Past, Present and Future of St Martin-in-the-Fields, opened last week and runs till May 6.

But isn’t he suffering from status anxiety — or even vertigo — as he surveys how high he has climbed? “It’s the first time I have joined the grown-up world,” he smiles. “Those who were most radical in youth are the most right-wing by 60 (he is 53). I feel bits of myself in that, of becoming the grumpy old man.”

And how does the boy from Des Moines in Iowa, which is said to lack the charm of Milton Keynes, feel about arbitrating on Britain’s architectural heritage, separating the crowning jewels from the carbuncles? “I think I have been here long enough to earn the right to criticise,” he says crisply. “But I accept my appointment is controversial: I have been quite rude about certain British institutions.” Indeed, the British provincial restaurant never quite recovered.

Now, though, he has done ranting; instead, he wants to celebrate Britain. “The British always complain, but actually nothing is that bad here, even the railways; they are really no worse than anywhere else.” Still, despite our failure to notice that we live in paradise, Bryson would rather we continue to scowl than adopt the American smile: “The ability to criticise is based on insight; with Americans, there is a total lack of insight.” Ouch; a dangerous sentiment for one who is, at last, big — even fashionable — box office Stateside.

He says we Brits should cherish our heritage, not because it is old, but because it is beautiful. “I love cream teas, not because they are a tradition, but because they taste good. Only 400,000 buildings are listed in Britain, and 98% of applications for change of use are granted. You can develop alongside the old. Don’t throw out the good old stuff, rip down some of the ghastly Sixties stuff.”

So isn’t it indefensible, John Prescott tearing the Victorian heart from northern cities such as Liverpool? “English Heritage had ordered me into political purdah during the election, but I am smiling in agreement with you.” Bryson can’t do silence for long. At least in the 1960s, he continues, we had an excuse: “I came across plans for the destruction, or at least the rebuilding, of Bradford from the Sixties, and you can see how it must have seemed very exciting. But now we know the result.”

An infuriating paradox, he contends, is that as we grow richer, our new buildings grow poorer. “Architecture is now bolting together hundreds of sheets of tin to make a B&Q superstore.” He stops: “Agh! I really am drifting into grumpy old man territory.”

Humour should save him turning into a curmudgeon. But the Japanese should brace themselves, they are the next target of the Brysonian pen. “They are remarkably like the English,” he reflects, stroking his beard. Worrying, this, for Tokyo sorts: if they thought Clive James was hurtful, just wait for Bryson. I mean, look what he made of us: he averred that a defining quality of Britishness is that a saloon bar will engage in a long debate about the most efficacious route to Truro, even though no one plans to venture there.

Bryson has whiled away many hours in country pubs, leaving him a little rotund and slightly yellow in the teeth (ironically a feature that an earlier American said most disgusted him about the British). Bryson now feels a baffled tourist in his own country. Watching the news on a recent trip to Michigan, he says: “A 16-year-old girl had been killed crossing a road and the police chief was asked why they didn’t make it easier for pedestrians. He looked puzzled and said nobody had ever tried to walk across the road before.”

What appeals about Britain is its “agedness”, while America, he regrets, fails to protect what little heritage it has. “In my home town I would struggle to find anything that survives from my childhood. Friends were buying a house in New Hampshire from 1806, and they were tearing it down to build a new one.”

Brutal though hunger for modernity might be, isn’t that what makes America vibrant? “True, but you need a balance. Britain has already modernised a lot; it is incomparable to when I arrived (in 1973). This is about as good as it gets. The quality of life has improved while we are appreciating the heritage that was just being ripped apart when I came. It has successfully reinvented itself after running two-thirds of the planet.”

How does he stand on the cricket test? “I feel at home here. I cheer for England in the football.” Indeed, his application for British nationality is fuelled partly by his frustration at being unable to vote on May 5 — but also partly to avoid American death duties. “It would be unfair on my wife,” he says morbidly. Death does seem to be weighing on him, however prematurely; later, over a glass of red wine, he tells me he has missed his chance to write fiction as “soon I will be 60 and my productive writing years might be gone”.

Yet the very need to worry about death duties reflects years spent atop the bestseller list; for a former sub-editor on The Times, he has built up quite a pile (talking of which, he and his wife Cynthia bought a pile in Norfolk after their return from America two years ago).

Opposed to the Iraq war, Bryson really did leave America, in stark contrast to those celebs that talked a good emigration, yet remained earning their greenbacks under Bush. Bryson’s motivations were more personal than political, but what happened to all those refuseniks? “Oh, I know about 10,000 who would be happy to come over here. A lot of Americans are moving to New Zealand because it is far enough away and safe.” Blimey, that does sound drastic.

It also sounds like rich material for a new Bryson book, but then the old boy delivers a surprise. “I never wanted to be a travel writer, actually. But after the first one, my publisher said the small number of people who are paying you attention will expect another travel book.” The problem is that while his quirky, almost anti-travel writing, was ground-breaking, it has spawned endless imitators: “I don’t think I could write another thing about bad food. You can only be disappointed by a meal in so many ways.”

Still, while mocking Britain, his tone has always seemed affectionate. Was that, I ask, a ploy to curry favour with our book buyers? “Not really. You can take the piss out of the British and they love it; as soon as you are positive they feel uncomfortable.”

How, one wonders, is Bryson looking forward to another slice of deeply English life — high table? “Well I will be coming after both of you for money,” he says, pointing to me and the vicar of St Martin-in-the-Fields, the Rev Nicholas Holtam, a fellow Durham graduate.

He insists he does not want to be a mere figurehead chancellor and would like to increase the number of Africans at the green-welly university. He describes Durham as “the perfect little city”, which he contrasts with the “ugliness” of Oxford. Reward, this, for a university long in the shadow of Oxbridge that considered several senior politicians as possible chancellors before settling on Bryson.

But undergraduates hoping he will become a high-profile opponent of top-up fees are in for a shock. His children, David, Catherine, Felicity and Sam, have experienced American and British education, and Bryson discovered a US degree effectively costs $100,000 (£53,000), so he thinks our students should appreciate their varsity days are a bargain. “The fees here are pretty modest and I think people should pay some of their way.”

He also reckons (heresy this) universities should be forced to “go out and hustle for money rather than just be given it”. His son is completing his medical studies here after starting in America: “He thinks the British system compares favourably, and the students are more adult. But he does think the infrastructure here appalling. I keep explaining American universities are like country clubs: they boast how comfy their rooms are, how good the broadband access is, but the education is not really mentioned.”

That, he says, is because “everyone in America, even policemen, has to go to university now”. And while he welcomes universities being opened up to those from underprivileged backgrounds, he fears ministers’ increasingly American approach of sending everybody to university regardless of need or academic attainment will destroy the great generalist British education.

Doesn’t he romanticise Britain? After all, this is a man who can describe the National Health Service as “a glory”. “No, I’ve lived here too long for that. But I was surprised I wanted to come back after only being in America 24 hours. My (British) wife loved it there and enthused about how polite everyone was and I just smiled weakly. It was like moving back in with your parents in middle age.”

Even the American mantra about customer service, he came to see, was baloney if you asked for something unexpected. “I found this on a book tour recently. None of the hotels will let you into your room before 3pm. I would say, ‘But if checkout was at 11am, surely the maid has cleaned the room by now?’ You really want to go in, but you just aren’t allowed. You can almost be in tears.”

Hang on a sec. Surely he is not saying now that our dreaded landladies, who terrified young Bryson — pontificating on how to flush the loo — are preferable to their beautiful, polite, manicured, perma-smiling American cousins? He leans back and smiles, hands resting contentedly on a satisfied tum, and he stares out of the window: “For some ineffable reason I prefer it here. If you want to get rid of me, you are going to have to kick me out.” Hmm, one day, perhaps: but not before the Establishment doles out a few more baubles.

Arise, Sir Bill?