Almost a decade has passed since the handsome Mr Sheridan, now 35, became Scotland's foremost (living) working-class hero, while spearheading the campaign against the poll tax, the Thatcher policy which, more than any other, sealed Scotland's political estrangement from London.
Mr Sheridan was voted on to Glasgow City Council in 1992 as he languished in Saughton Prison, Edinburgh, for refusing to pay the tax. The vote was a show of solidarity from the working-class estates of the Pollok district of Glasgow where Mr Sheridan grew up, and to which he returned after university to incite poll tax protests.
On the eve of the elections to Scotland's Parliament, he has graduated from the Tories' bogeyman to menace New Labour. For Mr Sheridan's tiny Scottish Socialist Party (1,200 paid-up members) could, according to some polls, hold the balance of power in the new Parliament, elected by proportional representation. The SSP could sneak into Holyrood with as many as eight seats.
Sitting in his office, beneath a poster in which Margaret Thatcher metamorphoses, in two neat, easy steps, into Tony Blair, Mr Sheridan, though cautious about poll predictions, clearly revels in the possibilities PR offers to little parties. "The SSP holding the balance of power is Donald Dewar's nightmare scenario," he smiles. "But we could just find ourselves in that position."
If the "nightmare" comes true, New Labour can expect no mercy from an SSP packed with the militants it expelled on the long and bloody road back to electability.
South of the border, Mr Sheridan would be dismissed as a left-wing loony. And even in more socialist Scotland, a few denounce the Pied Piper of Pollok as a dangerous "heidbanger" who, behind an egalitarian front and matey humour, is manipulating the masses.
Many Scots, however, admire the man even when they dislike his politics. For while he has been eulogised by some journalists as the "most gifted politician of his generation", he has rejected career advancement to champion his class. Some 14 years after graduating from Stirling University he lives in a Pollok council flat, chasing up housing complaints, agitating for the revolution, and surviving on a pounds 6,500 annual councillor's allowance.
His living-room is a shrine to socialism. Lenin gazes down from above the gas fire. On the opposite wall is a picture of John Maclean, one of the Red Clydesiders, whose dream of a Scottish people's republic caused David Lloyd George to send tanks to Glasgow.
Maclean was the father of Scotland's romantic independent socialist tradition. Mr Sheridan carries the flame. With Scottish New Labour barred from coupling nationalism with socialism, the SSP is hoping to receive Labour supporters' second votes.
Mr Sheridan has developed militantism with a cuddly, human face. He flaunts his adoration for his trade unionist mum, Alice, and offers visitors homemade shortbread from a Tupperware box. Pictures of his girlfriend, Gail, an air stewardess, are pinned to his office wall alongside Lenin.
Two years ago his home answering machine informed callers that he was probably out fighting the Tories. Now it reports: "I am probably out fighting Blair and his new Tories."
Those who warn that he is concealing the dangerous reality of his political beliefs also have to battle against boy-next-door good looks. And in Mr Sheridan they come with touching human vanity.
"Where do you get the tan?" asks a journalist at a poorly attended SSP press conference of Mr Sheridan's Derek Hatton-style permacolour. "At Bellahouston Sports Centre," he smiles. Council-run and "pounds 1.65 a sunbed session".
And while po-faced militants stick rigidly to Marxist tract, Mr Sheridan is happy to chat about the personal. With middle age looming, has he never regretted not ditching idealism, donning the suit and mouthing the New Labour script? "Nah," he says. "I could never have lived with myself." But principles, he confesses, are harder to keep. Gail is 35 and they are both broody. pounds 6,500 a year is hardly going to raise a child, though a Scottish MP's salary would. Even pounds 20,000 - the salary the SSP has promised its members would only accept if elected - would be a fortune.Reuse content