THE SNP propelled itself into a long internal debate on tax policy yesterday after its tax-and-spend image came under sustained attack from some its most influential figures.

Delegates were warmed to call for a business-friendly, wealth-creating economy after independence by party treasurer Ian Blackford - who is seen increasingly as a persistent critic of leader Alex Salmond. But at the same delegates insisted on keeping income tax as the basis of a progressive and ''socially just'' tax structure.

Party managers immediately moved to deny any burgeoning conflict on tax policy between Mr Blackford and his supporters, including the influential Kenny McAskill, who are seen as modernisers, and the leadership.

Mr Salmond later went out of his way to insist the SNP was still loyal to the cause of using income tax as the basis of social equality and that the SNP would not enter a tax-cutting auction with New Labour and the Tories.

As Mr Blackford claimed he had won the first round of the tax debate, pointing out there was now no SNP mandate for higher taxes, deputy leader John Swinney reminded reporters that the conference had also overwhelmingly supported taxing those best able to pay.

Asked if the SNP was still to be seen as a tax-and-spend party, Mr Swinney refused to be categorical, saying: ''Our policy is designed to generate wealth and to create entrepreneurial conditions. We have the opportunity to deliver fair and progressive taxation. It is a question of balance.''

Mr Blackford's distance from the leadership was made plain in an appeal for a wealth-creating post-independence economy when he took a side-swipe at the decision to put independence tenth in the SNP's Scottish election priorities.

Mr Salmond looked uncomfortable as Mr Blackford argued to applause that Scots would only embrace independence when convinced of its economic benefits. ''Never again, as happened in the Scottish parliamentary election, should we have independence as number 10 in our list of priorities. Independence is the priority of this party. It should be number one,'' he said.

He also savaged Shadow Finance Minister Andrew Wilson's remarks about Nationalists being free to feel British. Without naming Mr Wilson he damned his reported comments as ''intellectually bankrupt.'' Mr Blackford saluted the success of the Irish Republic in creating rapid economic growth. In four years to 1997 it had enjoyed growth of 41%, he said, compared with the UK's 13%. The same sort of growth was needed in an independent Scotland if it was to deliver high-quality social services.

Mr McAskill, long seen as on the left of the party, surprised some with his support for Mr Blackford, a wealthy Edinburgh banker. ''Times change and we have to recognise that,'' Mr McAskill said.

Mr Swinney and Mr Wilson will now spearhead a party review of taxation policy which, if Mr Salmond has his way, will offer the prospect of an independent Scotland which is business and investment-friendly and hostile to indirect taxation, preferring to use personal income tax as the basis for social provision.

While this would clearly distance the SNP from Labour, it would also raise the question of what levels of income tax the Nationalists envisage if and when power moves to Edinburgh. The review is expected to take as long as two years.