Dennis Skinner is a little suspicious when we speak on the phone. “Why do you want to talk to me? I don’t trust the papers.” I protest my innocence. “Well, there’s the fact that you’re standing again, and if you complete another five years, you’ll have been in parliament for half a century. Oh, and the paperback of your memoir is about to come out.”

“Is it?” he says “Nobody tells me anything.” Eventually he relents. “All right. You’d better come tomorrow. The weather looks better than the day after. If it’s raining, we’ll just be talking to people through their windows. Bolsover library at 12 o’clock. We can talk there and then go out campaigning. I just hope it isn’t raining. It was terrible today.”

I expect Bolsover, in north-east Derbyshire, to be a tough little industrial town, but it’s actually more a large, sleepy village. Skinner’s constituency, which he has represented for Labour since 1970, is a collection of 20-odd former pit villages strung across 30 miles of rural Derbyshire. This is now a green and pleasant land, gentrifying in parts. Neighbouring seats, undergoing similar transformations, are no longer Labour bankers, but Skinner’s still is. His election agent, Gary Ransford, expects the 11,000 majority at the last election to rise to 15,000-plus at this one.

Skinner is waiting for me in the little library when I arrive, and we talk at a small table in the fiction section. At 83 – and having survived a heart bypass and bladder cancer in the past decade – he is in remarkably good nick. He has carefully groomed, shoulder-length grey hair, a rheumy right eye that weeps later when he stands speechifying in the cold wind, and sports a natty jacket and red tie. He is, you sense, a man who cares about his appearance.

‘I’ve been very lucky’ … Skinner earlier in his career. Photograph: Daily Mail/Rex Shutterstock

But why on earth is he standing again at 83? He’ll be close to 90 if the next parliament runs its course – only Gerald Kaufman, standing again for Labour in Manchester Gorton at 84, is older. “Mainly because Cameron told me to retire,” Skinner says. “People seem to forget. He told me three times in parliament. If I’d have finished, it would have looked as if he’d scored a victory. He would have talked about it. The moment he said that, I knew I’d have to run.” But in any case, he doubts whether the parliament will last a full five years. “It looks a lot like 1974,” he says. “I would guess either Miliband or Cameron would consider doing what Harold Wilson did and having a second election.”

Skinner says he is standing up well to the rigours of his 12th campaign in Bolsover. “I’ve been very lucky. I used to be very athletic when I was a young man. I don’t know whether that’s got anything to do with it. I worked in the pit for more than 20 years and never had a serious injury. I was playing tennis way into my 50s, until my knees began to give me trouble, and I still ride a bike, although my last one was stolen from the House of Commons.”

Everyone is shaped by their upbringing, but Skinner is defined by his. His memoir, Sailing Close to the Wind, recounts growing up as one of nine children in a poor but loving mining family in Clay Cross, a few miles south of Chesterfield. Bright and articulate, he passed the 11-plus and went to a grammar school, but rather than try for university, chose to leave school at 16 and follow his father down the pit. When he started work at Parkhouse colliery, one of 10 mines close to Clay Cross, there were 700,000 miners in the UK – the vanguard of the Labour movement.

Skinner with Tony Benn (left) at the Blackpool Labour conference in 1982. Photograph: Daily Mail/Rex Shutterstock

Politics were in his blood – his father had been blacklisted after the general strike of 1926 – and in the 1960s he was a member of Clay Cross district council, a leftwing citadel that later fought a famous battle against the Heath government’s decision to raise rents for council tenants. He was also president of the National Union of Mineworkers in Derbyshire in the mid-60s, before being pressed to be Labour candidate for Bolsover, a role he claims he never sought.

He made a series of vows – no junkets, no drinking in the Commons bars, no pairing with Tories – and is still clinging to them 45 years later. He says that’s why his majority has remained rock solid while others have dwindled. “I’ve survived because I had a set of principles and took decisions about expenses 20 years before the trouble came out in the press.”

His father told him to “treat parliament as a workplace and to keep my eyes on what the others were up to”, and he has always seen being an MP as an ordinary job, just like working in the pit. That’s one reason he likes to get to the House early. “When you’re a miner, you have seven yards [of coal seam] to cut, so you’d get five yards under your belt, then have your snap knowing there were only two left.”

Skinner is the embodiment of the “them and us” politics of the 1960s and 70s, but does that still play in our fragmented world? “Of course it does,” he says. “When I talk about getting rid of the bedroom tax, I tell people about Buckingham Palace. It’s got 60 spare rooms, but they haven’t got a spare room subsidy, as Mr Cameron calls it. Why not? That was a nasty piece of work, the bedroom tax, and I tell people how we’re going to get rid of it.”

Skinner campaigning in Bolsover, Derbyshire. Photograph: Christopher Thomond for the Guardian

The bedroom tax is one of the key themes in the stump speech I hear Skinner make half a dozen times later. Bedroom tax bad; mansion tax – “which will be paid by millionaires down south” – good. That, plus an attack on the zero-hours contracts at Sports Direct’s nearby warehouse, is the thrust of his brief, powerful appeals, delivered through loudspeakers attached to Ransford’s car.

It’s old-style politics in the raw. “He’s done all the same streets as he did in 1979,” says Ransford, who has been alongside Skinner in every campaign since, and been his agent since 1992. “It’s bananas that keep him going,” says Tom Speed, a flat-capped volunteer with a walking stick who is handing out posters. “This is how we used to do it. Then TV came along, and they thought, ‘Lets leave it to David Dimbleby’,” says Skinner. “I’ve never had less than a 10,000 majority, and I’m sure it’s because we do this.”

Is Ed red enough? “No”, he says. “He goes part of the way, but I’d go further. I would take rail back [into public ownership]. The parliamentary Labour party has never been a leftwing party.” Has it been frustrating to spend a lifetime standing up for lost causes? “Life’s like that. You have battles to fight. I never had the idea that somehow or other I was going to get to the end of the rainbow.”

David Cameron called him a dinosaur, but he doesn’t care. “I’ve never bothered about what people say about me. I understand why they do it, because sometimes they haven’t got an answer.” Skinner is not slow to dish out abuse of his own. He called Tory minister John Gummer “the wart on Mrs Thatcher’s nose”, liked to refer to Paddy Ashdown as “Paddy Pantsdown”, and in 1984 was expelled from the House (an occupational hazard for Skinner) for calling David Owen a “pompous sod”. At each state opening of parliament he punctures the flummery with a well-chosen greeting for Black Rod. “Ayup, here comes Puss in Boots,” he said in 1988, starting a tradition. Skinner, parliament’s great vaudevillian, revels in political knockabout.

Dennis Skinner berates David Cameron over a cabinet reshuffle in 2012 – video Guardian

Another of his vows was that he would never accept ministerial office – a possibility he tells me James Callaghan floated in 1976. “I said, ‘Jim, I don’t want to upset you, but you can, let’s say, give me a junior ministerial job looking after the coal industry, and I open my mouth a bit too wide and then you’ve got to sack me. What’s the point of that?’” But you would have had the chance to change things, I say. “You change yourself,” he replies. “It’s patronage.”

Skinner, assuming he is re-elected, will be one of four MPs – assuming the other three veterans, Kaufman, Michael Meacher and Ken Clarke, also hold their seats – to have been in the Commons since 1970. Kaufman would become Father of the House, by virtue of having been the first of the four to have been sworn in, and that suits Skinner just fine. “I wouldn’t take Father of the House even if I was offered it,” he says. “The idea that the Speaker is going to say to me [affects plummy voice]: ‘And now I call the Father of the House’ – you must be joking. I made it clear long ago that I wouldn’t do it.”

Even many of his enemies now call Skinner a “national treasure”, but he refuses to be neutered. When I join him and a group of supporters for a cup of tea at former councillor Eileen Goucher’s house, I can understand the appeal of this tight-knit community. He is “Den” to everyone, old triumphs are relived – “Me and Eileen have never been defeated in an election”, he says – and on the living-room wall is a painting lionising local mine workers.

There is a magnificent relentlessness to Skinner. I am exhausted by the end of the day, while he charges on. It has been a privilege to observe him in action, and he is kind enough to drive me back to Chesterfield once the last constituent’s hand has been shaken. But I have mixed feelings by the end. What’s it all for? He says the fact he hasn’t changed after 45 years is his greatest strength. I wonder if it might be his greatest weakness.

Sailing Close to the Wind is published in paperback by Quercus on 14 May (£9.99). To buy it for £7.99, visit bookshop.theguardian.com