Frank Gallagher (played with mesmerising panache by David Threlfall) has been chucked out of his local, The Jockey. Again. As he staggers drunkenly down the rain-drenched streets of the Chatsworth estate, he is chanting: " Make poverty history cheaper drugs now!"
As a car burns in the background well, it is the Chatsworth Frank decides to take a leak into a hole in the ground. He has failed to notice that the hole contains an electrical generator. As a strong current crackles up his stream of urine, Frank is severely electrocuted and keels over. He comes to hours later, in a hospital bed, highly bewildered: "I just woke up with this sheet on me head and I know for a fact that I did not join the Ku Klux Klan!"
Frank is told he has only days to live, and like a certain former prime minister he embarks on a frantic attempt to secure his legacy, trying to make amends for his long list of misdeeds. Haunted by the terrible things that happened to him in childhood, he's visited by an apparition of his 14-year-old self. The youngster rails against the adult Frank for peeing his potential up the wall: "I could have done something, been someone," rants the boy. "Instead of which, I became you. What's the point of you?" As Frank remonstrates with the lad, who is invisible to everyone else, another Jockey punter tuts at him: "You're a walking advert for abstinence, you are."
This coruscating opener to the fifth series underlines Threlfall's description of Shameless as "The Simpsons on acid." Such a riotous episode (it's also directed by Threlfall) is par for the course in Paul Abbott's hit Channel 4 series. Since 2004, it has been the most outrageous and outrageously enjoyable drama on television, consistently echoing the sign that hangs above the entrance to the set in Manchester: "Proud to be Shameless!"
The drama has captivated a loyal army of fans, often seen wearing T-shirts proclaiming: "I blew my Giro down The Jockey". I chaired a question-and-answer session after a screening of Shameless at the British Film Institute, and it was packed with aficionados who appeared to know more about the series than its makers. The show is a multiple award-winner, and has even received the (perhaps questionable) accolade of a prime ministerial mention.
I'm meeting Threlfall, 54, for a rare interview at a private club in west London. The bar all armchairs and designer cocktails is worlds away from The Jockey. The actor chooses a seat by the window so that, he says wryly, "from time to time I can gaze wistfully at the outside world".
He's a fascinating interviewee, fizzing with ideas and showing a neat line in dry wit. At one point, Threlfall gestures at his "look" stubbly chin, faded jeans, old white T-shirt and a zip-up top that has seen better days and deadpans: "As you can imagine, I'm often consulted about fashion. 'What do you think of Marc Jacobs?' they ask. 'I don't know,' I reply, 'I don't support Arsenal.'"
Threlfall, who like Frank hails from Manchester, ponders the story of how the Gallaghers made it to Downing Street. "I believe Tony Blair was talking about the family and he referred to Shameless. He was obviously trying to divert attention from Iraq futile plan! But the fact that the then prime minister mentioned the series shows what an impact it has had."
Indeed, Shameless's many fans still mob the show's stars wherever they go. Threlfall says: "People come up to me all the time and shout, 'Frank, you pisshead! We love you!' I've certainly not had anyone say to me, 'That show is detestable!'" But the attention can become overwhelming. "The last time I was in a pub in Belfast, I had to leave because I was mobbed. I love the fans, but it can get a bit full on."
Just why are the Gallaghers so loved? At first glance, they look like a horrifying, irredeemable bunch of work-shy, Asbo-inviting chavs, hooked on handouts, the neighbours from hell. And yet, when Abbott plunges us into their world and we start to see things from their point of view, we feel a glow of affection. Their creator has, not entirely tongue-in-cheek, compared the Gallaghers to the Waltons.
Threlfall who says the Gallagher family motto should be: "If you can't stand the heat, blow up the kitchen!" reckons that we experience a frisson in seeing this dysfunctional family go into places that we, in our safe homes, would never dare enter. "People love the Gallaghers because they know they're not them. They think, 'There but for the grace of the Gallaghers go I.'"
Shameless seems to have universal appeal. "It doesn't just attract the lower end of society," Threlfall says. "I've had people from right across the social spectrum tell me they get it. Sometimes reporters ask, 'Don't you think you're being a bit patronising about working-class people?' To which I say, 'Bollocks, you middle-class journalist!' If it was condescending, I'd know because the people on the estates where we film would come and tell me.
"Without sounding cheesy, Shameless has such broad appeal because it's about humanity. Everyone knows someone like Frank, fuelled by bravado and self-delusion and yet still lovable. And everyone can feel for those children, who are forced to look after themselves and sometimes behave in extreme ways. You either get it and love it, or you don't and switch over to I'm a Celebrity...
"People like Shameless because it's a slice of life in fact, it's a veritable VC Black Forest gateau of life," the actor declares, before adding, with a self-deprecating laugh: "If you print that, I'll come and hunt you down!"
Few characters are, on the face of it, more repellent than Frank. A compulsive social-security scrounger who fakes his own death in order to escape the bailiffs, head-butts his gay son and steals from his children to fund his drug habit, he seems the ultimate loser. But viewers adore him.
"On the surface, he is not a very likable character," Threlfall concedes. "But through the writing and, I hope, the performance, he becomes in some way redeemable and lovable. Also, people feel Frank's vulnerability. There is a sense of something lost about him. You can trace the way he treats himself and his family back to what he learnt growing up. Now he's adrift and he tries to make up for it by having an opinion about everything.
"Having said that, his behaviour is often on, or beyond, the limits of what is acceptable. It's very liberating to express that. But I have to put Frank down carefully at the end of each day. I have to leave him on set. I don't want to take him home with me."
Frank is also celebrated for his often bizarrely convincing rants. "He has a licence to say the things that we all think but no one would dare utter out loud. Without sounding grand pretentious, moi? in Frank's mouth the most banal things can sound magic. It's like verbal painting. He's forever trying different styles. He's Jackson Pollock one day, Salvador Dali the next. I'd better not continue with this analogy, or I'll end up in Pseuds Corner!"
There's little chance of that. Threlfall was brought up in the Manchester suburb of Burnage, and until he went to the Manchester Polytechnic School of Theatre, he'd been expected to follow his father into the building trade. He has two children and is married to the actor Brana Bajic (Lena in Shameless series two).
So where did the actor find Frank, one of the most iconic TV characters of the age? "I just rolled back the sheets and there he was," smiles Threlfall, who admits that before being cast as Frank a role for which he won the RTS best actor award last year he was in a lean period. "Paul says Frank is 50 per cent him and 50 per cent me, but I think when I was offered it, the character was kicking around inside me."
One aspect of Threlfall's performance that people love is the way he throws himself into it in the most gloriously uninhibited fashion. "You just have to go for it," he says. "It reminds me of my favourite line from Hollywood. When the Merry Men are invited to a feast in Errol Flynn's Robin Hood, someone calls out, 'To the tables, everybody, and stuff yourselves!'"
Off set, though, traces of Frank are hard to spot in Threlfall. Where Frank is drunk and disorderly, Threlfall is savvy and sharp. But the actor's credibility in the role underscores what a remarkable chameleon he is. He burst into the national consciousness as a heart-rending Smike in the RSC production of The Life and Adventures of Nicholas Nickleby in 1979. A friend of mine who worked in the Aldwych Theatre bar at the time says that even after watching Threlfall's performance a hundred times, he never tired of it.
Since then, the actor has made his name by transforming himself into utterly different characters. He has incarnated everyone from Frank, the prince of chavs, to the Prince of Wales in Diana: Her True Story. It is hard to believe that his two most recent TV performances as the vivid, exuberant Frank Gallagher and as the dry, shrivelled, emotionally repressed husband Will in Victoria Wood's Bafta-winning Housewife, 49 are by the same actor.
Threlfall may be a reluctant star, but he is feted in the industry for his star quality. Dominic Dromgoole, the artistic director of the Globe, regards him as the new Alec Guinness. "He's a funny mixture of a star and a character actor," Dromgoole says. "He takes character acting to such super high-definition accuracy that it becomes a star performance. He's brilliant."
Threlfall has that rare ability to vanish into a role. "I'm more interested in other people than myself," he says, before checking himself with a smile. "People will say, 'You're an actor give over! Don't be so bloody daft.' But I'm truly happiest folding into the background."
To do that, Threlfall feels he must maintain an aura of mystery which is one reason why he rarely gives interviews. "In Charlie Chaplin's autobiography, there is this section about when he's travelling by train from the West Coast to the East Coast of America. There are huge crowds waiting at the station in New York, but Chaplin doesn't understand why they're there. His companion explains, 'They're here for you. You'll be invited to all the parties here, but go to very, very few of them. The more you go to parties, the less people will come to see you in the theatre.' You must retain some mystique.
"I'm a very private type. For me, the publicity game of 'Please watch this show, ladies and gentlemen' is like pulling teeth. I like the work to speak for itself. This is who I am, but that is what I do."
For this reason, Threlfall loathes the prevailing culture of celebrity. "I couldn't tell you what reality TV is all about. The idea of coming home and watching people locked together in a room well, it's not for me. And I don't understand magazines like Hello! and OK!, either. People will think, 'Oh, you miserable sod,' but I just don't get things like that."
Threlfall hasn't always been seen as the easiest person to work with; Trevor Nunn once described him as "a handful". But now, his collaborators have nothing but praise for him. Has he mellowed?
"I've always liked becoming different people," he reflects. "It used to be because I didn't know who I was. But now I think, 'Get over yourself.' I used to take roles home with me because I was frightened that I would lose touch with them. But there is no room for that; now I leave them on the mat with my shoes. I understand that there are more interesting and important things in life. That realisation comes with experience and maturity." Pause for effect. "And any day now, I'll acquire those qualities!"
The actor embarks on another analogy. "I'm not anxious or paranoid about things. The train has left town and I'm fortunate enough to be on it. But I know that one day it'll stop and I'll have to get off it." He's laughing again: "I can't believe I'm using this metaphor!"
The main thing, Threlfall stresses, is that in his business one has to remain flexible. "Was it Tennessee Williams who said, 'Not to change is to die'? Anyway, he's dead, so he can't sue! It's more difficult to change as you get older you're more set in your ways. But as an actor, you have to be able to tap into openness and vulnerability the qualities that help me to play Frank and Will in Housewife, 49." Threlfall will be reunited with Wood when she reads his debut radio play, Stupid Cupid, on Radio 4 on Valentine's Day next year.
The actor's rather off-kilter perspective on things can also benefit his work. "I'm certainly not insane, but I am a bit surreal. Mike Leigh said that of me. I'm drawn to different ways of looking at the world. I love people who do that like Dali, or Billy Connolly, or some bloke you meet in a pub in Belfast. Those people can give you a different slant on the world."
So, Frank apart, what does the future hold? Threlfall is devoting more time to his role as an ambassador for Save the Children, one of the charities this newspaper is supporting in its Christmas Appeal. "In February, I went to Ethiopia to see a health centre set up by Save the Children, and it was quite a salutary experience," he says. "My parents used to say, 'Remember there are children starving in Africa.' They were right there are. I've seen them and it's very upsetting.
"I just have to close my eyes and I can still see the orphan kid I met who has to limp for miles and miles to get to the health centre. But the money goes such a long way in Africa; just 1,700 will supply a medical centre with drugs for six months. Having got a profile as Frank, this is the only way I'm interested in using it."
On the professional front, Threlfall is hoping to work more behind the camera. He has directed four episodes in the new series of Shameless. "I love bossing people around," he jokes. "No, what I really love is the chance to connect in different ways with all the departments on a drama.
"It's also a big help that I can understand what the actors are going through. I'm very straight with them. On a long-running show, you get the opportunity as director to say, 'You know that thing you do? Don't do it!' I like to be surprised by people." But it can be hard to direct himself. "You do feel like a split personality, but it's manageable. Sometimes I have to say to myself, 'Get better. Your energy's low.'"
Shameless has already been commissioned for a sixth series (to transmit in 2009), and Threlfall feels there are plenty of new places to which the creative team can take the characters. "Paul and I have had meetings about it, and we've got a tremendous amount of ideas for the next series. I'm still really passionate about it."
Threlfall shows the same relish for everything he does. "Before Shameless, I had a couple of years where things were a bit tough. I couldn't give it away. You see some bloody actors moaning about everything. But I know many fine actors are not working, so you'll never hear me complaining.
"I love going to work. When that dwindles, I will go and do something else. I have signed on for another year doing Shameless, but I won't be doing much until April. That will give me time with the family, who think at the moment that I've gone missing in a canoe off the coast of Hartlepool! 'Who are you?' 'I'm your father. I've been in Manchester for seven months and had amnesia!'
"I'm really lucky. This work floats my boat. I'm allowed to dress up and pretend to be someone else as thoroughly as I can. I love it. Fill your boots, I say. To the tables, everybody, and stuff yourselves!"
The fifth series of 'Shameless' starts at 10.10pm on Channel 4 on New Year's Day