‘I’ve had enough. It’s time to pack it in,” declares Michael Parkinson, the 72-year-old king of the British chat show. “I’m a bloody dinosaur!”

This Saturday, millions of people will tune in to see Parkinson in action for the last time. The departure of a talk show host doesn’t usually cause an outbreak of heartfelt farewells. Did we mourn the passing of David Frost, Simon Dee, Russell Harty or Chris Evans? We did not. And in the future will anyone weep for Wossy?

People say that when Parkinson thanks his guests and those final credits roll, it’s more than one man’s retirement; it’s the end of an era.

“That’s true,” says Parkinson. “My kind of chat show, the kind based on conversation, is finished. Today all the shows like Jay Leno or Jonathan Ross are built around the host and are more about comedy than conversation.”

Parky fans fear that now he’s going, all we can look forward to is a future of overpaid presenters sucking up to undertalented celebrities. So what does he make of today’s generation of hosts? Not much. I suspect he regards them as vulgar, illiterate show-offs searching for sound-bites and poking around private lives they have no place in.

He doesn’t come out and say that, because Parkinson is far too diplomatic and he doesn’t want to sound like an old grumpy guy. So instead he tells me: “I couldn’t do the kind of show that Jonathan Ross does and he couldn’t do mine” - which is a polite way of saying Ross is a useless interviewer.

Unlike Ross, Graham Norton or Paul O’Grady, Parkinson is not a colourful character. He was never a wisecracker like Clive James or a quick, caustic wit like Clive Anderson. No, Parkinson has always presented himself as an ordinary bloke. Like Barry Norman, he came across as cosy and comfy as a pair of old Hush Puppies.

But I’ve always wondered if beneath the old Parky no-nonsense plain-speaking Yorkshireman persona there lurked a dark side. I thought I might find it when I heard that fellow chat show host O’Grady had once said of him, “He likes to think of himself as a miserable git.”

Is there, I wondered, a deep strain of melancholy running in that sensible soul of his?

Parkinson laughs off the very idea. “Miserable? Me? Not at all. I know how lucky I’ve been to have this job and last so long.”

What about Parkinson the lothario of the leather seat? “He flirts like mad,” says Lenny Henry. “I think women tend to flirt with him,” says Julie Walters.

It’s said that on occasion the sexual impulse breaks through Parkinson’s suave exterior - and it’s not a pretty sight. George Melly wrote of Parkinson’s “inability to control his lust while talking to actresses. A frightful saloon bar leer takes over as he leans towards them”.

The singer Charlotte Church once complained that, “Michael Parkinson asked me, ‘How’s your sex life?’ and I said, ‘Mr Parkinson, are you serious?’ He went, ‘Oh, sorry, I shouldn’t have asked that’. Damn right he shouldn’t, he’s old enough to be my grandad.”

But despite his notorious on-screen flirtations there’s never been a whiff of sexual scandal about Parkinson, who has been married to Mary for almost 50 years. But he is a lifelong jazz fan who used to spend time with rather louche company - drug users and dealers - at Ronnie Scott’s club in the late Fifties. Did he ever smoke pot? “No, no pot for me. I’m a Yorkshireman and we drank. Booze was our drug. There came a point when I was drinking too much and decided to quit.”

I give up and am forced to conclude that Parkinson really is what he seems: a down-to-earth Yorkshireman with a passion for sport, jazz and the novels of Ernest Hemingway. If he has a secret it’s this: he’s a lot smarter, serious and more sophisticated than the star-struck interviewer we see on our screens.

You may not be a fan, but the rise and retirement of Parkinson says a lot about the cultural life of the nation and particularly its changing relationship with celebrity over the past three decades. Unlike today’s media wannabes, Parkinson never wanted to be famous; he was a newspaper man who stumbled into television production. In 1971 the BBC asked him to front a new talk show. “Nobody had any great expectations,” says Parkinson. “It was just a cheap bit of cheerful telly to fill in an eight-week gap in the schedule. No one thought it would last.”

In the 1970s Parkinson’s show often pulled in 11m viewers. Why? “I’m a good listener,” he says. “Billy Connolly said I was the best audience he ever had. My role is not to be intrusive.”

I suspect Parkinson’s success has a lot to do with the fact that when his show first began, stars and celebrities weren’t such a ubiquitous feature of national life. We were living in a pre-Hello! Britain. Stars on the box were a rare treat - we got an extra portion on the Morecambe and Wise Christmas special.

Watching Parkinson interview the likes of Muhammad Ali, Henry Fonda and James Cagney was a big event. The television chat show gave us a sense of intimacy with these people. Thanks to Parkinson we had these legends in our living rooms every Saturday night.

Parkinson agrees. “I was lucky to have people like Muhammad Ali on my show five times - he was then the most famous man in the world. There’s been no one like him before or since. And people could see the great Hollywood legends like Fred Astaire. They’d never seen these people in conversation before. When Astaire came down those stairs it was electric.”

When Parkinson says he’s a dinosaur, he’s actually right: his own tastes and style of talk show are rooted in a star system that is vanishing fast. What has happened since he first began his show is that stars have become an endangered species, their place on the fame chain replaced by an ever-growing number of celebrities. What’s the difference? Elizabeth Taylor is a star; Elizabeth Hurley is a celebrity.

What has taken place since the 1960s is the death of the star and the rise of the celebrity. Critics of contemporary celebrity culture forget that Britain in the 1930s and 1940s was a star-struck society.

When George Orwell wrote in his famous essay The Lion and Unicorn about the private pleasures of the English, he mentioned the passion for crossword puzzles, gardening and pigeon racing, but not film stars.

But American film stars - the kind Parkinson admired - had an incredible influence on the way people dressed, talked and even kissed. The writer JG Ballard has said, “People don’t realise what a godlike aura the stars of the cinema had for people back then. We put them on pedestals.”

Today no sooner do we place them on the pedestals than they get pushed off to make room for a new face. Parkinson, despite the odd lapse, is really of the old school that doesn’t believe in prying too deep or pushing a celebrity too hard. Young audiences want to see a dash of rudeness and irony from hosts such as Ross and company. “But why?” says Parkinson. “You can’t go on the attack in something that is essentially a bit fluffy.”

So when does he believe the big change from stars to celebrity began? “Maybe it goes back to the Thatcher years when success became a matter of money. But in terms of television it’s only happened in the past 10 years.”

It’s true that the 1980s were the decade celebrity magazines such as Hello! took off. The rise and influence of Madonna led to the creation of a new social type: the wannabe - a girl who wanted to be famous like her idol. We also had the kids from Fame on the television and Bros singing their teenage anthem When Will I Be Famous?

Parkinson can’t understand the way young wannabes think. “It’s got out of control. There’s far too much celebrity on the telly. They even have courses on how to be a celebrity at university. What for? They don’t even know what it means. We have lost any kind of common sense about this.”

But isn’t he television’s Dr Frankenstein, the man who helped create the bloated beast that is celebrity culture?

He looks a little disgusted. “Not at all. I never let those people on my show.” But he has interviewed Sharon Osbourne and Victoria Beckham, two figures who epitomise talent-free triumph. Parkinson is quitting because he knows his time is up.

“I was telling the audience what my father said just before he died. He said to me, ‘You’ve done all right for yourself. You’ve met some famous people. You made some money - but it’s not like playing cricket for Yorkshire, is it?’”

And I said, ‘No, Dad, but once or twice it got pretty damn close!”

Parkinson: The Final Show will be screened on ITV1 on Saturday at 10.15pm

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