Why Rab C Nesbitt is still a vested interest

Times are tough for Rab C Nesbitt, the Buckfast-sodden philosopher in the rancid string vest. Back for his 10th series, 25 years after he first shook a newspaper and held forth in his broad Govan vernacular, he is struggling to stay sober. His wife Mary Doll's cleaning company is falling apart. "The first thing the middle classes give up in a recession," says Rab's long-suffering, leopard-skin-coat clad missus, "is their cleaner and their sponsored child in the third world."

On pre-Rab TV, the underclass experience was confined to the occasional World in Action documentary. "He was the first guy to refer to himself as scum," says writer Ian Pattison. "He took ownership of that term; it was in his first monologue." Nothing was off-limits; Rab C Nesbitt was a defiantly black comedy in which violence, incest, rape, alcoholism and substance abuse were all fair game for gags. Now, with The Royle Family and Shameless operating in the same territory, this material seems more familiar – but it was Rab who first battered open the door with a disgusting old shoe, then kicked it down with the help of a bunch of bams (idiots) from The Two Ways Inn.

Gregor Fisher first shrugged on Rab's crusty suit as part of Naked Video, a BBC Scotland sketch show, in 1986. Despite being loathed by the city fathers, who thought he undermined their attempts at economic revival via culture, the character span off into his own series in 1988 and ran until 1999. When a tentative revival – a Christmas special in 2008 – attracted five million viewers and a Bafta, a new series followed in 2009. Later this month, series 10 will introduce the milder shores of the UK to the gallus Glesga patter once again.

Pattison, who grew up on the grey streets around the south banks of the River Clyde himself, is delighted and apprehensive about giving Rab's manky headband another turn around the block. "It's not a challenge writing-wise. But what will people think? Will they stone me in the street? That is not what we want."

Common sense dictated that, in the 10-odd years between the new series and the show's earlier incarnation, there had to be some changes. The most important is that Rab, previously a sherry-on-the-cornflakes kind of guy, has cut down on the sauce. "Otherwise he would be dead, and there would be no show." Mary Doll and vinegar-tongued Ella Cotter are mumtrepreneurs. Rab and Mary have a granddaughter, Peaches. Rab still prefers old fashioned time-wasting methods to Facebook et al, but he is aware that they exist.

"You can't make it so absurd as to be unbelievable," says Pattison. "Rab is not going to tweet. But we needed somewhere new to go. So he's not drinking but his friends are, and we see how they react. Everyone knows that going to the pub when you're sober is really boring.

"I didn't dare put the women in the same position, so they've got a business. That brings dynamism to their relationships. The men are lagging behind the ladies. What does that say about their manhood?"

Govan, once the proud home of the city's shipbuilding industry, latterly a deprivation hotspot, has also evolved – and while it is no one's idea of a garden suburb, it is wall-to-wall Wine Alley no longer.

The political landscape of Scotland has also changed drastically since 1986; Rab arrived while Mrs Thatcher was Prime Minister and devolution a day dream. Now he is a citizen of Alex Salmond's brave new Scotland.

Yet if Rab is an anachronism, he is one that Scots are in no hurry to throw in the dustbin of history. According to Pattison, what keeps him warm in our affections is his self-awareness. "It's his saving grace," says the writer.

"He knows his limitations and his weaknesses. There's nothing you can say about him that he has not said himself."

The 10th series of Rab C Nesbitt begins on 5 October at 10pm on BBC2