If she hadn’t pointed it out, I probably could have guessed that the bright pink car parked at Kettering station belonged to Shirley Clarkson. Jeremy’s mother was bound to be driving something special and it turns out he arranged to have it sprayed, knowing she loves pink.

“I’ve got the nail varnish to match!” she says cheerfully and roars off into the Northamptonshire countryside, regaling me with tales of her three boyfriends.

At 74, Shirley is – predictably perhaps, given her motor-mouthed son – an enthusiastic talker whose sentences always seem to end in exclamation marks. She forever has a project on the go or gets “terribly, terribly bored”, so she’s just bought a converted chapel to do up – “It’s got three staircases and I was supposed to be downsizing!” – and is planning a big party for family and friends at the 12th century Oakham Castle in Leicestershire to celebrate her book.

Life’s been one long party for Shirley, really, born with that gift beyond price – the ability to see the funny side of everything, and a thick skin, which comes in handy because one of the (admittedly few) downsides of being Jeremy’s mother is that everyone who discovers who she is gets the urge to tell her exactly what they think of him.

“And the telephone calls!” she exclaims. “I get telephone calls that start, ‘Shirley, do you remember me? We went to school together in the Forties . . .’ And before they’ve finished the sentence I say, ‘Sorry, he’s too busy’.”

The salve for this affront to her dignity is that people sometimes contact Jeremy’s office asking if it’s possible to get a new eye or ear for their beloved old Paddington Bear (Shirley having created the original), but still she cringes at the thought that people might think she’s “cashing in” on her son’s success.

The truth is, though, that unlike some of the “relatives of . . .” tendency, Shirley really does have her own story to tell, in her authentic Yorkshire voice. Officially, her book chronicles the creation of her Paddington Bears and the ups and downs of running a small business amid the turbulent industrial relations of the 1970s, but it also paints a picture of a nononsense Britain – before it was hijacked by political correctness – that shaped both mother and son’s thinking.

Her memories of stuffing toffee papers up the nostrils of The Dying Gladiator at Castle Howard during her schooldays foreshadow the same breezy disdain for his schooling that Jeremy showed later at Repton. “He was very bright, but he wasn’t interested in algebra or physics,” says Shirley. “He kept saying, ‘Oh, who wants to know?’ He didn’t want to learn anything. He used to say, ‘I don’t need this because I’m going to be a television presenter.’ And we just said, ‘Oh, don’t be stupid, Jeremy, get on and do your homework’.”

While Shirley and her husband Eddie were building up what was to become their Paddington Bear empire, Jeremy continued to nurture his dreams of becoming a journalist and joined the Rotherham Advertiser as a cub reporter. “He didn’t enjoy that very much. He didn’t enjoy pony club meetings on a Sunday afternoon,” says Shirley, “so he packed it in.” With no job to go to, he took up his parents’ suggestion that he work for them and become a Paddington Bear salesman. But while Eddie – for all his accidents and antics – was an assiduous salesman, noting down the details of shopkeepers’ wives and families so he could ask after them the next time he called, it was a life for which Jeremy was never cut out.

“He liked the job because it meant he could live in London and have a firm’s car – albeit a white sports car, open-topped,” says Shirley. “He was supposed to do the whole of the south of England but he’d get down to Penzance and then a girlfriend would ring and say there’s a party in London tonight and he’d zoom back up. He did quite well, mind you – shopkeepers liked him. But he and a friend set up an agency writing about motoring and that was the end of that.”

Eddie did not live to see Jeremy’s success. “No, it’s terribly sad, because he was so proud: Jeremy had just got onto Top Gear and was a sort of junior member of the team. And of course the one thing Eddie wanted more than anything was grandchildren, and he held Ben, my daughter Jo’s newborn son, for about 10 minutes and then he died.”

But however proud he might be, Eddie would surely be as bemused – and amused – as anyone by a petition on the Downing Street website proposing Jeremy as prime minister, signed by nearly 50,000 people. A similar petition on Facebook has attracted 160,000 signatures. “It’s people wanting someone with a bit of common sense,” says Shirley, firmly. “He says things which everybody wants to say but daren’t. He doesn’t hold back; he says what he feels. It upsets some people, I know, but he doesn’t suffer fools gladly.

“It’s so funny because my daughter’s husband, John, is incredibly clever, very well-read, but he’s very PC – so sit him at a table with Jeremy and you can imagine! They can have a discussion about religious wars and Jeremy’ll be sounding off, then John’ll have his turn and the rest of us can only sit back and watch.

“They’re both very bright but diametrically opposed. When Jeremy rings his sister and wants to speak to John, she’ll say, ‘John, it’s Adolf on the phone,’ and if John rings Jeremy’s house they say, ‘Dad, it’s Che Guevara’.”

Shirley moved down from Doncaster to Northamptonshire a few years ago to be near Jo and help with the children and takes an obvious delight in helping with the fetching and carrying from school and being part of their lives. “My granddaughter wants a disco dress, so I’m still sewing,” she says.

One thing that pains her is that Jo, a hard-working solicitor with a London firm, doesn’t get the recognition she deserves, with the spotlight so often trained on her brother. “Joanna’s played as important a part in everything as Jeremy, but she’s the head-down type with two degrees, went to university then went to law school and has got where she’s got with hard work,” she says loyally.

“And there’s Jeremy with two degrees – honorary – and Jo says, ‘Honestly, I was four years getting my degree and Jeremy just gets his through the post’.” (Though someone did shove a custard pie in his face when he was being awarded his degree at Oxford Brookes University.)

“Jo’s the sensible one, the one who’s got us through everything, but really, they’re both wonderful,” she says. Which leaves her with an awkward dilemma. The very first Paddington Bear she made, the prototype for her business, is now insured for £20,000. “There’s two of them and only one of him,” she says. “So what happens when I go?”

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