Britain:Gordon Brown has put the Conservatives on the defensive while casting himself as the champion of the unionist cause in face of the rising nationalist threat in Scotland.
On the eve of the 300th anniversary of the legislation affecting the Act of Union, Mr Brown - the Scottish chancellor who expects to succeed Tony Blair as prime minister later this year - warned of a "dangerous drift" to separatism and the threatened "Balkanisation of Britain".
And he daringly claimed the mantle of Margaret Thatcher for himself in charging that "some Conservative writers" were now embracing "anti-unionist" positions - "from independence to 'English votes for English laws'" - which he described as "a Trojan horse for separation".
With some polls now suggesting majorities in England and Scotland favouring independence, Mr Brown said George Orwell had rightly ridiculed the old left for interpreting patriotism as little more than the defence of unchanging institutions "and for posing a false choice between patriotism and internationalism".
But he noted that "the failure to defend and promote the United Kingdom" was now becoming "more a feature of the thinking of the right".
That prompted a denial yesterday from Conservative leader David Cameron, who said there was no question the union had made both England and Scotland stronger, and assured he would be celebrating the anniversary of the Act of Union in May.
However, some Conservative sources were perplexed by Mr Cameron's countercharge that Mr Brown was trying to "intimidate" Scotland into remaining within the union by way of rhetoric raising "fear of the economic consequences of going it alone".
Mr Cameron asserted the unionist case must be made "with the heart as well as the head".
However, one traditionalist said privately he feared Mr Cameron had "got the argument the wrong way round" because sentiment might incline Scots to go for independence whereas "the economic argument is the great unknown . . ."
With the Scottish National Party riding high ahead of the Scottish Parliament elections in May, Mr Brown's intervention was widely seen as the opening move in an effort to forestall a threatened crisis over his expected assumption of power in London after Mr Blair finally steps down.
As a Scottish MP Mr Brown would have little or no say over policies affecting his own constituents, a product of the unresolved "West Lothian Question" that has prompted some Tories to even question whether a Scot can successfully serve in Number 10.
Writing in Saturday's Daily Telegraph, however, Mr Brown said "a national debate about Britishness and the future of Britain" was overdue, and that the 300th anniversary of the Act of Union was the appropriate time "for supporters of the union to speak up, to resist any Balkanisation of Britain, and to acknowledge Great Britain for the success it has been and is".
Drawing a contrast with Mrs Thatcher, "who rightly defended the union and did so even when not expedient to do so", Mr Brown said the union was now under attack from "an opportunist coalition of minority nationalists and from what used to be the Conservative and Unionist Party", which he said was "forming around a newly fashionable but perilous orthodoxy" emphasising what divided rather than united the country.
While referring to the United Kingdom, Mr Brown made no direct reference to the Union of Great Britain and Northern Ireland.