It's an unfair cop: Gene Hunt, the most defiantly un-PC PC on the block, is back

The desk is strewn with tell-tale signs that we're in the office of a real man's man. The keys to an Audi Quattro. A tumbler full of whisky. A pack of Players No 6. A picture of footballer Ray Wilkins. A Betamax tape of Escape to Victory. But the clincher is a mock-up of one of those old Wild West posters. It reads: "The maverick sheriff cleans up town."

That's right, we're taking a tour of the office of DCI Gene Hunt – played with rare panache by Philip Glenister – the maverick sheriff whose wilfully unreconstructed attempts to clean up town have turned him into one of the most popular of TV characters. He is the defiantly un-PC PC.

By any objective standards, Gene should be a loathsome figure. Across two series of Life on Mars and two of Ashes to Ashes (the second begins next week on BBC1) he has revealed himself as a dinosaur detective. He has no time for reading suspects their rights, breezily proclaiming that he has invented "the bruise-free groin slap".

When his by-the-book colleague Sam Tyler (John Simm), who had been transported back to the 1970s from the present day in Life on Mars, once berated him as "an overweight, over-the-hill, nicotine-stained, borderline-alcoholic homophobe with a superiority complex and an unhealthy obsession with male bonding," Gene retorted: "You make that sound like a bad thing."

In Ashes to Ashes, which is set in the early 1980s, Gene enjoys some equally sparky clashes with another right-on modern-day colleague, DI Alex Drake (Keeley Hawes). She has been sent back to 1982 from today and is constantly horrified by Gene's casual sexism. This is, after all, a bloke who, in 1973, declared in his characteristic, I'm-never-wrong tone: "As long as I've got a hole in my arse, there'll never be a female prime minister." He's the man political correctness forgot.

And yet, in spite of attitudes that would barely pass muster in the Stone Age, Gene is a hugely loved character. So why has this Neanderthal proved so ridiculously popular? "Gene is so well loved because he's gruff and difficult to please," says Hawes, 33. "He's the opposite of a New Man. People really like that. It's such a breath of fresh air. Someone who exhibits those old-fashioned ways in this PC era is very attractive. What more could you want?"

Glenister, who possesses a waspish wit, is in civvies today. He has swopped Gene's trademark naff coat and gloves for a jersey with a Richmond Golf Club logo on it. The actor admits to being taken aback by the extent to which Gene has struck a chord with people.

"It's amazing and fascinating how this character has become part of the public consciousness," he says. "But Gene certainly seems to resonate with viewers. I think he stands for a freedom of speech that is being eroded. There's too much red tape and an obsession with health and safety. Every little thing becomes an issue. A tiny bit of snow and the country grinds to a halt. One of the perks of this job is that I get to test-drive cars. I was supposed to test-drive a new Aston Martin DB9 in February, but unfortunately it got stuck in the snow. Not very James Bond, is it?"

Donning an air of Gene-like assertiveness, Glenister adds: "People are fed up with bureaucracy and the 'targets' culture this government has instituted. Let teachers be teachers and doctors be doctors. Stop telling everyone else what to do – that's a sign of someone who doesn't have a proper job. Get a life, Mr Secretary of State for Sod All!"

This fictional detective is immensely popular with real-life coppers. "The police love him because he represents a bygone era which they miss," reflects Glenister, who's married to the actress Beth Goddard and has two daughters. "I present an award every year at the Police Bravery Awards, and they all tell me they know someone just like Gene. There was a poll to see who should replace Sir Ian Blair at the Met, and a lot of people voted for Gene!"

Gene is also an unlikely sex symbol. Why? Hawes, who sports a 1980s poodle perm and white leather jacket in Ashes to Ashes, reckons that "women feel Gene would look after them. It takes such a lot to get a compliment out of Gene that if they ever did, these women would melt."

Glenister, 46, who's appeared in Demons, Cranford, Calendar Girls, State of Play, Hornblower, Clocking Off and Vanity Fair, treats Gene's heart-throb status with amused detachment. "It's a dirty job, but someone's got to be hot. If it's not going to be Alan Titchmarsh, it has to be Gene.

"I get invited to give speeches at a lot of weddings. If I get all these invitations to speak, how many must Stephen Fry get? I told one couple I couldn't make it, so they asked me to send a cardboard cut-out of myself with a button you could press to hear my speech. What was I going to say to them? 'Don't marry her, you're ruining your life, kid'? Maybe there's a business opportunity there..."

The actor is very protective of his alter ego. "Gene's a wonderful character to play. I feel very precious about him. He's been so good to me. He's like my child; I feel an overwhelming sense of responsibility towards him. I'm sure it gets up some producers' noses, but it's because I care."

The first series of Ashes to Ashes had an air of levity about it. This time, the show has a darker tone. The series, set in 1982, is played out against a backdrop of the zenith of Mrs Thatcher's power and the Falklands War. The overarching theme of the series is police corruption. And more is revealed about Alex's frantic attempts to return to the present day.

"Part of the fascination of Ashes to Ashes is the mystery of how Alex ended up in the 1980s," says Hawes, who has also starred in Mutual Friends, Under the Greenwood Tree, Tipping the Velvet and Our Mutual Friend. "The plot for this series is incredibly byzantine. We've actually been told why Alex is stuck in the past. All the hairs on the back of our necks stood up when we found out."

The first Ashes to Ashes enjoyed healthy ratings, but was not such a hit with the critics. Some disappointment was inevitable after the high expectations generated by Life on Mars, but it still attracted some 6.6 million viewers every week.

One of the allures of Ashes to Ashes is the saga of Gene and Alex's "will they, won't they?" relationship. "It's such fun," Hawes says. "I can't say if anything happens between them. But I really like that element."

I ask Glenister what effect Gene Hunt has had on his career. "I was doing OK before Gene, but he has moved me on to the next stage. It happens to a lot of actors. For instance, Doctor Who has elevated David Tennant to Planet Success."

Glenister's certainly getting more offers. "You have to learn to say no. But you also have to be wary. There comes a point where people think you can't do anything else but Gene. I got sent a script where the main character was a poor man's version of Gene with none of the charm or charisma. He was just a one-dimensional policeman."

'Ashes to Ashes' starts on BBC1 on 20 April