We must be able to be worthy of the trust of the voters and there is no better place to earn that trust than in our own internal democracy and financial dealings

Ian Blackford

Mr Salmond said that while his wife's airfare had been paid for initially by the SNP, that money was later refunded by the European Institute, which he had travelled to Brussels to address.

Mr Blackford, an investment banker, said he had been unjustly accused of being responsible for a deficit estimated to have been about �400,000.

His attack came during a fringe event at the Eden Court Theatre conference venue in Inverness.

Mr Blackford, who held centre stage for The Sunday Times lecture, made it clear that he favoured leadership hopeful Alex Neil's strategy for moving Scotland towards independence and not that of fellow contender and current deputy leader John Swinney.

Ian Blackford talks to the media

Mr Blackford reiterated his view that his suspension following a vote by the national executive in June was a breach of "natural justice" and he was being held responsible for the profligacy of others.

He said: "John Swinney over the last few weeks has talked of the importance of trust, that the SNP must work hard to achieve the trust of the Scots.

"I agree with John and it's fair to say that today that a large percentage of voters do not trust politicians.

"We must be able to be worthy of the trust of the voters and there is no better place to earn that trust than in our own internal democracy and financial dealings."

'Costly' newspaper

Mr Blackford said he had been foiled when trying to rein in costs after the Scottish parliamentary election campaign and the heavily criticised and costly Scotland's Voice campaign newspaper.

He said: "Those responsible for spending rather than cutting expenditure actually continued to spend above budget.

"Over the last two years, it is fair to say that I have sought to control expenditure and there are those who have challenged this.

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"After consultation with our travel agent we set limits for expenditure in a number of cities in Scotland.

"There was one office-bearer in particular who would not abide by the limits that were accepted by everyone else.

"I had to write to the office-bearer to state that I did not consider it reasonable for the party to pay for part of their travel while the said officer was on a speaking engagement in Brussels.

"The issue of taxi bills has also been raised and I do not find it acceptable in this party, when finances are always tight, for any individuals to spend up to �1,000 a month regularly on taxis."

Mr Blackford said that despite opposition from party leaders, he was determined to seek re-election as treasurer at this year's conference.