The Scottish National Party is accusing the Scottish Executive of hyping up the sums made available through Chancellor Gordon Brown's spending review.

However, ministers say they are standing by the figures and have accused SNP of a political "gaffe".

John Swinney accused ministers of a "con"

Finance Minister Andy Kerr will announce this week how �4.1bn is to be spent over three years.

The money was earmarked for Scotland in July's spending review, although the Scottish Executive has the final say on how the cash is spent.

The SNP argues that this figure hugely overstates the real money being made available.

Leader John Swinney said Treasury documents showed that only �100m would be added to the value of Scottish spending in the next year - rather than the �1.5bn being claimed by the government.

He said this was down to a combination of old money already announced and a change in accountancy practice.

Already announced

"Labour is engaged in a massive con against the Scottish public," claimed Mr Swinney.

"They have engaged in an outrageous attempt at Enron-style accounting.

"First they changed the way the figures are calculated to increase the total without adding a single penny to spending, and then they added in money that has already been announced.

He has got it completely wrong and I look forward to him eating a very big portion of humble pie

Andy Kerr Finance Minister

"The result is that they have been claiming a spending bonanza and spinning stories about huge improvements in transport and the public services, when in fact the money is little more than a figment of their imagination."

His accusations have infuriated Labour ministers, who condemned what they described as disgraceful allegations.

They said that the SNP had spotlighted a single Treasury column which dealt with an accountancy adjustment.

Mr Kerr said the cash available to the Scottish Executive would definitely rise by �4.1bn over three years.

He said Mr Swinney had made a political gaffe - and suggested that the SNP leader should be worried about Thursday's announcement.

"He has got it completely wrong and I look forward to him eating a very big portion of humble pie," he added.