TWO leading independence campaigners have spoken out against Alex Salmond's plan for a currency union with the UK if Scots vote to go it alone next year.

Jim Fairlie, a former deputy leader of the SNP, said the most sensible option for an independent Scotland would be to establish a new currency.

Colin Fox, the leader of the SSP and a Yes Scotland campaign board member, also backed a new currency, arguing the proposed currency zone would hand power and control to the Bank of England.

They spoke out a week after Chancellor George Osborne warned the UK was unlikely to agree to a currency union with a newly independent Scotland. If the UK did agree, he added, it would place considerable constraints on Scotland's economic policies.

Mr Fairlie, who is no longer an SNP member, dismissed the plan in an article for Options for Scotland, an online forum set up by former party leader Gordon Wilson. He admitted an independent Scottish currency "may cause a level of nervousness" but said it was the only option to provide full control of economic policy.

He added: "If sovereignty means anything at all to the Scottish people, control of their own currency is a prerequisite."

Mr Fairlie's comments were backed by Mr Wilson, who said the currency union plan was undermining the pro-independence campaign.

Mr Fox wrote in his blog: "It goes without saying that keeping the pound or establishing a sterling zone means handing over a considerable amount of power and control over Scotland's economy and spending options to the Bank of England and the City of London. And many will in-evitably ask what then is the point of Independence?"

Their comments echo views voiced by Jim Cuthbert, an economist frequently cited by the SNP, and John Kay, a former economic adviser to the First Minister.

The pro-independence Scottish Greens have also urged the SNP to keep the option of a new currency open.

Pro-UK campaigners seized on the remarks.