Speaking in Glasgow, the Prime Minister said that Scots faced a choice between "devolution or divorce" in the Scottish Parliament elections, to be held on 6 May. He went on to accuse the SNP of treating social justice as secondary to national identity, and of "proclaiming patriotism" instead of policies.
"You cannot evade choices about Scotland's future by wrapping yourselves in Scotland's flag," the Prime Minister said. "For there is at the heart of the SNP's approach the dishonest assertion that anyone who scrutinises the SNP is seeking to subjugate Scotland.
"It is wrong for any political party to claim that it and it alone speaks for the nation and that for any of its political opponents to question that party is for them to attack the nation."
The Prime Minister's attack was delivered as he addressed an audience of Labour candidates and supporters at the Royal Scottish Academy of Music and Drama during a day of engagements in Glasgow.
Despite advance protestations by Mr Blair that he and Labour were not merely crudely "Nat bashing", the SNP remained firmly in the party's sights yesterday.
Arriving in Glasgow, Mr Blair's first engagement was to unveil a campaign poster which, in huge headlines, shrieked "Divorce is an expensive business. It won't be a trial separation with the SNP".
"On 7 May, one of two things will happen," said the Prime Minister. "Scottish New Labour will go to work for a stronger health service, better schools and a prosperous economy. Or the SNP will file for divorce from the rest of Britain."
Mr Blair went on: "The decision the Scottish people will make is whether this election will be remembered as devolution day or divorce day."
He accused the nationalists of being more interested in "the trappings of the nation state", and more interested in national anthems than the national health service.
"Their ambition is not that the devolved parliament succeeds but that the devolved parliament fails," Mr Blair said.
"At root, they remain a party of protest, not a party of power."
The nationalists had a clearer idea of how to increase Scotland's taxes than how to increase Scotland's prosperity, said Mr Blair in an attack on the SNP's economic plans. "The SNP began as the party of division. They would take office as the party of divorce. They would end as a government of economic decline."
Labour, by contrast, offered the vision of renewal on the basis of shared values that made Scotland stronger with Britain and Britain stronger with Scotland.
The SNP's leader, Alex Salmond, greeted Mr Blair's visit to Scotland by attacking the Government's record on public spending. Speaking in Glasgow, Mr Salmond said: "Tony Blair talks about delivering, but what London Labour are actually delivering is cuts in our vital services.
"At the end of the three years of the Comprehensive Spending Review, spending in Scotland will still be lower than it was under the Tories. The squeeze that Labour is imposing on Scottish public spending will leave Scots much worse off over the next few years, relative to the rest of the UK."
Mr Salmond said Scotland's health service would be pounds 500m better off over the next three years if it received the same percentage increases in spending that apply in England.
"Instead of Nat bashing and talking Scotland down, Tony Blair should use his visit to Scotland to explain why key public services are being run down by Labour mismanagement."Reuse content