DEREK Mackay has said an independent Scotland could keep the pound indefinitely, just days after SNP members demanded a new currency be fast-tracked.

The Scottish Tories claimed the Finance Secretary was in “full retreat” after he emphasised the caveats attached to his party’s new policy, rather than its merits.

Mr Mackay also stressed the SNP’s proposals involving keeping the pound initially, and Holyrood would decide if there should be a change, subject to six stringent tests.

He said: “Our position is clear. Until a new currency can be safely and established in the interests of the whole economy, the currency of an independent Scotland should continue to be the pound sterling.

“It will be for an independent Scottish Parliament when the time is right - if there is that change - based on the right economic position for Scotland.”

READ MORE: Iain Macwhirter: There’s no need for the SNP to take a pounding over currency issue 

Delegates to the SNP’s spring conference voted on Saturday by 781 to 729 to establish a new currency “as soon as practicable”, subject to six tests.

The vote was a surprise defeat from Nicola Sturgeon and Mr Mackay, who had advocated a more gradual approach, with no new currency for at least a decade, in keeping with the SNP's Growth Commission.

The policy shift offered the First Minister’s unionist opponents, including newly returned Scottish Tory leader Ruth Davidson, a ready target to attack the Yes movement.

In an urgent question at Holyrood, Labour MSP James Kelly asked Mr Mackay what impact a new currency would have on business.

READ MORE: SNP members support new currency as soon as practicable 

Mr Mackay said: “Firstly, our proposals are to keep the pound in the immediate term, and an SNP government will take steps necessary to enable the Scottish Parliament to authorise the preparation of a Scottish currency as soon as practicable after independence.

“The Sustainable Growth Commission established by the First Minister in her capacity as SNP leader produced a detailed report on the financial, economic and regulatory requirements necessary for the transition to an independent currency.

“It engaged extensively with businesses in developing its recommendations. It recommended the introduction of six tests to guide that transition, one of which is the financial requirements of Scottish residents and businesses.

“Those tests were back by SNP conference on Saturday. Our position is clear. Until a new currency can be safely and established in the interests of the whole economy, the currency of an independent Scotland should continue to be the pound sterling.”

Mr Kelly said the SNP wanted to drop the pound immediately, devaluing savings, and would make Scottish families and business “significantly worse off”.

Mr Mackay, who was on the Growth Commission, said he was “delighted” the currency resolution he co-authored was passed - after activists added “as soon as practicable”.

He said: “We have set out, in terms of currency, the position that we continue with the pound. We’ve set out the tests that will guide our decisions.

“It will be for an independent Scottish Parliament when the time is right - if there is that change - based on the right economic position for Scotland.

“And those tests - fiscal sustainability, central bank credibility, financial requirements of Scottish residents and business, sufficiency of foreign exchange and financial reserves, fit to trade and investment patterns, and correlation of economic and trade cycle -  these are sensible tests that would guide such a decision.”

Tory MSP Murdo Fraser said: “It’s only been three days since the vote at his conference and already the cabinet secretary is in full retreat from the position set out at that conference.”

He asked what work had been done on the “extra transaction costs” for Scots firms trading with the rest of the UK - Scotland’s biggest export market - using a different currency.

Mr Mackay said: “We will be keeping the pound on independence, and of course we can build our options as an independent country.

“We’ve set out the tests that we would apply to any potential change of currency.

“We’ve set out our preferred position. And we’ve also shown, really importantly, how our economic policies would  be enhanced if we had the powers of independence.

“That would grow our economy, deliver greater fairness and empower us to make the right decisions by the people of Scotland.”

In response to SNP MSP Bruce Crawford, Mr Mackay agreed the currency would remain the pound after a Yes vote and only change when an independent parliament decided that.

“Our policy is that we will support a change as soon as it can done safely and securely in the interests of the country, the economics of the country, when the time is right.”

Mr Mackay’s comments followed more criticism of the plan to ditch the pound.

A former member of and an adviser to the party’s Growth Commission both questioned the move, saying it could jeopardise people’s savings and was not a priority.

Richard Marsh, an external adviser to the Growth Commission, warned savers and householders could he hammered if the new currency has less value than sterling.

In 2013, the Scottish Government’s own Fiscal Commission Working Group warned a new currency was a “significant undertaking in the short-term”, though not unprecedented, and Scotland would need to “re-denominate all domestic wages, prices and contracts”.

Ms Sturgeon’s special advisers were unable to say at the weekend whether a new currency would be pegged to sterling - with the Scottish pound worth the same as a UK pound, for example - or float on the international money markets, and potentially be devalued.

Mr Marsh said devaluation could wipe out years’ of savings and leave 45,000 householders trapped in negative equity, as their mortgages were recalculated in the new currency.

He told the Scottish Daily Mail: “The Scottish Government may seek to absorb some of this risk to protect mortgage and asset values by pegging the currency.

“But [given] this could be at the cost of public services and delivery, this would be a difficult decision for any new administration to make.

“If Scotland took a ‘big bang’ approach with a new currency set up shortly after a vote for independent, then it would mean businesses, individuals and the Government would need to take account of movements in exchange rates between the newly established Scottish pound and sterling.”

Dan Macdonald, a former member of the Growth Commission, said currency was “almost irrelevant” compared to economic growth and “secondary” in the independence debate.

He said: “We need plans for the economy over the next five to ten years. That is more important than any one issue, including the constitutional question - we need to build the economy first.”

Financier Peter de Vink, a friend of Alex Salmond who backed Yes in 2014, said a fledgling independent Scottish currency would be a magnet for speculators.

The director of Edinburgh Financial and General Holdings said the result could be worse than Black Wednesday in 1992, when speculators made millions betting on sterling’s devluation, sending interest rates soaring.

He said: “The pound was devalued by 25 per cent and that was in Britain - Scotland is a tenth of the size, so it would be even more of a problem. It would be devastating.

“It is cloud cuckoo land stuff if they think they can do it. I thought there would be a little more brain power.

“[At] the last referendum, we avoided the currency issue as much as we could because we all knew it would be the most difficult thing.

“Talking about a currency is all wishful thinking if you haven’t got a strong economy, and Scotland is not going to have a stronger economy if Scotland continues to have higher taxes than the rest of the United Kingdom.”

An SNP spokesperson said: "Scotland will keep the pound immediately after independence.

"The SNP's policy is to make a managed and responsible transition to an independent currency, only when it is safe, secure and practicable to do so."