The signs on Glasgow's Churchill Drive are ominous for Gordon Brown

"It's time." The SNP's slogan is as final as it is simple. After 300 years of disputatious union, the nationalists' shout of last orders suggests England and Scotland are draining their glasses before going their separate ways.

And this time, for the first time, they might be right. The SNP - for decades hobbled by an image as single-issue extremists - is on the brink of a stunning victory that would install it as a party of government in Holyrood. The polls may narrow over the next few days (the latest gives the SNP seven more seats than Labour) and there is a still a sizeable minority who are undecided, but most analysts now believe that Alex Salmond will win the greatest number of seats in the new Scottish Parliament when that body is elected on Thursday.

While he may still be denied the chance to form his own government - he will need the support of the Liberal Democrats - Mr Salmond will be in the box-seat in the horse-trading in the weeks ahead.

How did the Labour Party allow this calamity to befall it? And what will happen once First Minister Salmond and Prime Minister Gordon Brown square up across the border?

There could be few street names more British than Churchill Drive and few areas more associated with Labour's Scottish hegemony than Kelvin in Glasgow. The solid pebbledash semi-detached homes of streets like it have for years been part of Labour's bedrock. But now, in John Prescott's famous phrase, the plates are shifting. "It's hard to change the habits of a lifetime," says Margaret Meldrum, a lifelong Labour voter. "But I am part of the switch." Mr Brown, she says is "just the same" as Tony Blair in not seeming to care much for Scotland, while the SNP is "hard working".

But tellingly she adds that she wants to "keep with England". Support for independence has rarely been lower - just 22 per cent - but Mr Salmond has allayed voters' fears with the promise of a referendum before any split while promising to work in a spirit of co-operation with London in the meantime.

The reality, most observers agree, is that First Minister Salmond would, from the off, seek to exploit and magnify every conflict of interest between London and Edinburgh. His strategy would be to create the conditions for a "yes" vote that he hopes might even take place under a Conservative UK administration in four years' time.

And the signs for Mr Brown from this election are ominous. His allies lay the blame on the "Blair factor", cash-for-honours and the unpopularity of the Iraq war. More privately, Labour's leader in Scotland, Jack McConnell, is the target of the sort of backbiting at which Scottish politics excels. He is described by members of his own team as "pathetic" and "a joke".

But this distracts from the deeper reality - that Labour is failing to enthuse traditional voters while not winning any new support. Mr McConnell's administration is not seen as incompetent - just unlikeable. Voters, irritated by Holyrood's lack of real power are, at the same time, deeply irritated by its perks and privileges, and the dominant party takes the largest slice of the blame.

If Scotland sets itself on the road to independence this week it will be largely because of a protest vote against Labour rather than a vote for separation.

What happens next?

SNP wins well

The SNP win convincingly enough to form a minority administration. The Lib Dems, who hold the balance of power, honour their pledge not to form a "stop the SNP" coalition with Labour. First Minister Alex Salmond uses his mandate to defy other parties to block his main policies.

SNP wins narrowly

The SNP win just two or three more seats from Labour and require a coalition with the Lib Dems to govern. The price of a deal is that the nationalists drop their plans for a referendum on independence.

Lib Dems, the king-makers

The SNP and Labour achieve the same number of seats. The Liberal Democrat leader Nichol Stephen, below, is able to conduct a bidding war between the main parties.

Chronic uncertainty

All of the above could end in a second election being held this year. A minority SNP government might also fall to a vote of no confidence, while the other likely outcomes require a deal of sorts with the Lib Dems.

McCabe lashes out after gibe

After the "Prescott punch", Tom McCabe is the latest Labour politician to prove one can overdo the personal touch. Taunted by an SNP activist, the minister was filmed physically retaliating yesterday.

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