A tense and unpredictable power struggle is under way between the two most successful politicians in Britain: Prime Minister David Cameron and his opposite number in the Edinburgh parliament, Alex Salmond, the leader of the Scottish National Party.
To the astonishment of most Westminster politicians, Mr Salmond won an outright majority last May and pledged to hold a referendum on independence during the second half of his four-year fixed-term administration.
That was not just to give himself time to run a propaganda campaign. His main aim was to take advantage of one of the most emotive dates in the history of Scotland, June 24, 1314. The 700th anniversary of the legendary victory of out-numbered Scottish troops over a lumbering and poorly-led English army at the battle of Bannockburn will take place in two years' time.
Mr Salmond believes that the reminder of the struggle for independence in the 14th century will provide a psychological boost to his hopes of winning.
That may sound far-fetched, but Bannockburn has preserved an iconic significance, largely thanks to the poet Robert Burns, who celebrated it in a poem called 'Scots Wha Hae', which is sung every year at the party conference of the SNP.
The lyrics of the poem are every bit as fierce as the battle itself: 'Lay the proud usurpers low, tyrants fall in every foe. Liberty's in every blow. Let us do or die.' The 'proud usurper' these days is Mr Cameron, who is about to publish a legal opinion that his coalition government is the only one that has the power to decide the timing and wording of the referendum.
Mr Cameron claimed yesterday, rather dubiously, that the Scottish economy was being damaged by the uncertainty over what would happen. He declared that it would be 'desperately sad' to break up the UK
Mr Cameron knows that if Mr Salmond succeeds in shrinking the UK, the economic and strategic implications would be extremely negative.
The biggest immediate blow would be to the UK's role as a nuclear power, because its submarines are stationed in Scotland. The SNP pledged to get rid of them and there is, apparently, no suitable location on the coastline of England.
The struggle for control of the Scottish referendum process will move to the House of Lords this week, when anti-independence peers will try to pass a law giving all Scottish-born people the right to vote.
The move will be strongly opposed by the SNP, which fears that Scottish people living in England would be more likely to vote in favour of keeping the union.
The most crucial argument of all, however, will be financial. Union supporters are claiming that if Scotland went independent, the cost of personal and company loans would shoot up because it would no longer be under the UK's credit rating.
John Swinney, the SNP's shrewd finance minister, reckons this is nonsense and that, thanks to the revenue from North Sea oil, there would be no adverse effect.