Nationalists boldly go into the great unknown

SHE talks like a Sinn Feiner on the brink of throwing out the British. Her ambition is to break up the United Kingdom. In four days' time she will take a big stride towards her goal.

Roseanna Cunningham, a self-confessed "Trekkie" - an addict of the TV sci-fi series Star Trek ("it's the ultimate 'what if?'") - and martial arts practitioner is poised to humiliate John Major, taking the once-safe Tory seat of Perth and Kinross for the Scottish National Party in Thursday's by-election, brought about by the death of Sir Nicholas Fairbairn MP. Victory will also take some of the shine off the triumphal progress of Tony Blair's "new Labour".

The Government will write off the loss as another case of mid-term blues, but the Nationalists believe the result will indicate a permanent shift in voter preferences, hastening the day when Scotland opts out of the union with Britain. Be prepared for heady talk of watersheds, turning points and things never being the same again.

Ms Cunningham, 43, a lawyer,spent her teens in the other Perth, in Australia, after her parents emigrated from Glasgow in the 1960s. The family returned 20 years ago. She is already looking beyond joining her three SNP colleagues in the Commons, where she expects to be the party's environment spokesperson. She sees Westminster as a regrettable but necessary detour on the road to a home rule parliament in Edinburgh. "My next ambition is to be part of the independence negotiating procedure," she says.

A simple majority of Nationalist seats in Scotland will be the automatic trigger for secession, she argues. "If a majority of people have voted SNP, we would regard that as a right to say to Westminster 'let's sit round the table and negotiate'.

"We would ask the UN to be a neutral observer while we negotiate a package [on secession]. It would be SNP policy to put that package to a referendum to vote on specific proposals to cover the transitional stages. Assuming they vote 'yes' in the referendum, we proceed on that basis, subject to formal independence being declared. There would then be a general election in Scotland, to allow the Scottish people to choose their government." The possibility that London might resist the break-up of the 288-year-old union in such circumstances is, she says, "unthinkable".

"The English people would not allow their government to behave in that fashion. Once the will of the people has been expressed in a way that our system regards as final [i.e. first past the post; the SNP prefers proportional representation] we are prepared to say it is time for negotiations. I don't see that there needs to be any difficulty. Major has said that ultimately Scotland cannot be denied self-determination if that is what is wanted."

But is that really what is wanted? On Thursday, will the voters be plumping for protest or partition? The evidence hardly supports the SNP. A System Three poll for the Herald newspaper showed that 54 per cent of those intending to vote SNP did not actually want independence. Nevertheless, the most reliable poll gives Ms Cunningham 50 per cent of the votes. The bookies make her 6-1 on favourite; the Tory 66-1 against.

So the Conservatives are genuinely alarmed, not just at the prospect of losing another seat - bringing John Major's majority down to nine, with another dangerous by-election looming at Saddleworth and Littleborough following the death last week of Geoffrey Dickens - but at what may be read into an SNP victory.

They are appalled by "Red Roseanna's" republicanism (she described the Queen as "the pinnacle of the class system"), dismayed by her socialism (she supports a pounds 4 an hour minimum wage) and distressed by her anti-landlordism (she robustly asserts anglers' rights). They are scared out of their wits by the "Nationalist bandwagon gaining speed".

Unfortunately, the Tory candidate, John Godfrey, a 32-year-old merchant banker and former political adviser to Douglas Hurd, last week emptied both barrels into his feet, telling voters live on TV that if they must register a protest, to do so by all means, but not by voting SNP. The novel political ploy of telling one's potential supporters to vote for someone else (headlined in the Dundee Courier with masterly understatement as the candidate's "unusual plea") has eased Mr Godfrey into third place behind Labour. There is even speculation that he could finish fourth, behind Veronica Linklater, the jolly-hockey-sticks Lib-Dem contender, but the irreducible core Tory vote is probably too large for that. Shortly before his death, "Nicky" Fairbairn snorted that Mr Godfrey (who still believes the poll tax was "a great idea" that "went wrong at the margins") was an "unelectable clone".

Labour's candidate, Douglas Alexander, 28, a former researcher for Shadow Chancellor Gordon Brown, has been told to look less like a Blairist automaton and come out fighting. The party is pulling out all the stops to close the gap with the SNP, but officials are already privately preparing their alibis.

So Roseanna it will be. But the unresolved question will remain: is her victory a false dawn for the independence movement, or the real thing? More than anything in her sci-fi tales, that is the big "what if?".