Caroline Aherne

Caroline Aherne and Craig Cash rarely give interviews, so it's a real surprise to see them talking at such length about one of TV's best-loved sitcoms. Their anecdotes are often cut short by laughter, but we do get genuine insights into the meticulous way that the series is written, filmed and even edited. Such is the love for the pair that cast members and high-profile fans including Catherine Tate and Willy Russell all line up to pay tribute, but it's Cash and Aherne themselves who emerge as the most frank. For those who feel that the added slapstick of recent Christmas specials has severed the show from its realist roots, Cash's reasoning for the shift in tone will be of particular interest.

Caroline Aherne and Craig Cash, the creators of The Royle Family, take a lengthy look at just why their kitchen-sink comedy struck a chord. As several contributors suggest, it succeeded because it was observant, naturalistic and, as the screenwriter Jimmy McGovern (of Cracker) has it, "brilliant art".

Royle Family go behind the scenes for Gold specials

Caroline Aherne and Craig Cash to reveal secrets of UK's laziest family in two TV specials for digital channel Gold.

If anything was going to put you off your Ferrero Rochers over Christmas, it had to be The Fattest Man in Britain, ITV's comedy drama about a man in an orthopaedic armchair eating himself to merry hell. Timothy Spall looked dangerously at home in the title role as Georgie, with comedian Bobby Ball admirably cast as his "manager", Morris, turning up with a cabful of Japanese tourists eager to take pictures and lay their hands on the big man's folds. "I would ask you to respect Georgie's private zones," said Morris (though, frankly, you imagined these people might get enough blubber at home). Frances Barber completed the homely trio as Janice, who came in every day to shovel Georgie's meals together and grease his legs, which was as attractive as it sounds.

With Caroline Aherne co-scripting, there was as much pleasing northern drollery as you'd expect amid the ill-lit claustrophobic clutter and junk food and trash TV familiar from The Royle Family, though admittedly the oxygen tank looked ominous.

Things took a turn when a crew of youths was sent by the social services to tidy the garden and Amy - a pregnant teenager on the run from a violent boyfriend - ended up moving in. Aisling Loftus was excellent as the underfed, beaten waif looking for a father figure and finding it in kindly Georgie. There was a worrying moment, in his late mother's bedroom, when you wondered what kind of a comedy this was turning into... but no, Amy was soon settling in, cooking and tidying up, nibbling a dark chocolate Magnum with Georgie (not the classiest of product endorsements), helping Janice with his pig-sized legs and restyling his terrible 80s mullet - an early clue that he hadn't been out in 23 years. That's how long it had been since his mum died. "It's like I was eating for her," Georgie confided. "Like there was an angel on my fork."

All was well until a rival barrage balloon from Birmingham challenged Georgie to a TV weigh-in and Morris - aided by locals arriving with mountains of pizza and bakewell tarts - set to bulking him up for the contest. Amy - now almost as big as Georgie (well, not quite, but who remembered she was even pregnant?) - railed against the freak show that would surely kill him.

Events were channelled into a poignant denouement, but when the baby died and Amy called it a day with Georgie, it didn't feel like tragedy. Even when Georgie rose from his chair and struggled down the street to see her, it was more Love Actually than love. There was a late attempt at profundity with a short disquisition about the desire to make failure look like success. "If I'm not the fattest man in Britain, what am I?" cried Georgie. "I'm just a fat man!" It was a great line, but it just made me think that inside this broadly entertaining drama was a sharper, less funny one trying to get out.

Caroline Aherne and Craig Cash's wonderful observational sitcom about a working-class Manchester family who seem never to leave their sitting room is now going the way Only Fools and Horses did, with an eagerly awaited one-off episode each Christmas. Tonight's instalment, for which no preview discs were available, is deliberately unfestive, with Jim (Ricky Tomlinson) and Barbara (Sue Johnston) wondering whether to spend a cash gift from their children on a satellite HD box or their first trip out of the UK. Afterwards, at 10.00pm, the final series of Gavin & Stacey - a sitcom which owes more than a nod to the Royles - begins to wind down, as the Essex crowd go on an eventful trip to the beach.

From the title, you'd expect it to be a channel Five documentary, but The Fattest Man in Britain (ITV1, Sunday) is actually a drama, co-written by Caroline Aherne. Timothy Spall, looking quite at home in a fat suit, plays Georgie, a good-natured human bouncy castle in Rochdale. But the star is Bobby Ball, who plays Maurice, his agent. Maurice takes foreigners on guided tours of Georgie, for £11.50. It's in his interest to keep Georgie as big as possible. So he feeds him up, like a goose, for foie gras.

Some of the dialogue has a nice, natural Royle Family feel to it. But it's a bit silly really. And as sugary as one of the pop tarts Georgie keeps popping. "That's why this title is so important to me, Amy," he says to the nice girl who's come to live with him. "The Fattest Man in Britain. Because if I'm not the fattest, I'm just a fat man. Just a big fat man sat in his chair."

"You've already got a title Georgie: you're My Friend."

Pass the sick bag will you. And give that man a gastric band.

The Fattest Man in Britain looked as if it was going to be filed under Northern Grotesque. You had Bobby Ball in a cab promising his excited Japanese passengers "the eighth wonder of the world". And then you saw Georgie's pudgy hand reaching for the aftershave bottle and splashing it on underneath a bingo wing the size of a sofa cushion. When Timothy Spall, just visible inside his fat suit, began singing "Turning Japanese", complete with slitty-eye gestures, for his paying guests it looked as if we were in for an exercise of gleeful bad taste. In fact, Caroline Aherne's drama (co-written with producer Jeff Pope) turned out to be a lot sweeter and life-affirming than you might have expected, contriving a Beauty and the Beast relationship between Georgie and Amy, the community-service girl who came to clear his garden. For her, he was the dad she's never had; for him, she was the first person to care for him who didn't have an interest in him getting bigger. Although he was initially devastated by the realisation that he had a heavier rival ("If I'm not the fattest, what am I, eh? I'm just a fat man") he finally struggled out of his chair and slimmed down to win her back. I wasn't entirely convinced that it would have been as easy as it was made to look, but very happy to pretend while it lasted.

Last Night's TV - The Fattest Man in Britain

What a tour de force Caroline Aherne and Jeff Pope are. The Fattest Man in Britain was a modern day fairytale. Its sentimentality and morality message were not in-your-face obvious, but it without doubt left me feeling the goodwill to all men thing.

Helped by a top-form Timothy Spall in a fat suit, writers Caroline Aherne and Jeff Pope wittily poked and prodded at the fascination of the freak show, an industry fuelled by endless TV shock-horror reality exposes. 'I'm happy the way I am - look at the joy I bring to people,' claimed Spall's Georgie, a money machine for weaselly agent Morris who pitched up with taxiloads of foreign tourists for whom Georgie would karaoke Rio or Turning Japanese, as geography dictated. Georgie's journey from delusion to disillusion - 'If I'm not the fattest then what am I? Just a fat man, a fat man sat in his chair' - was pretty clearly signposted. And the tone bumpily lurched between broad farce and modern tragedy. But as Georgie's real self emerged from amid the self-protective folds of flab, only the hardest of hearts wouldn't have raised a cheer.

If you're worried about gaining the odd pound over the next few days, this should put things into perspective. It's a great, wobbling tale of a Rochdale man who's so obese he becomes a tourist attraction. Timothy Spall plays warm-hearted giant Georgie Godwin; his agent Maurice (Bobby Ball at his most terrifying) charges foreign tourists to line up in Georgie's front room and hear him sing bad karaoke.

The script is co-written by Caroline Aherne and has her characteristic mix of broad comedy larded with touching moments. The opening scenes rely heavily on caricatures, but stick around and things warm up. Music by Badly Drawn Boy leans the whole thing a poignancy the script doesn't always manage, but by the end you're left with the lingering feeling that you've seen a modern fable.