SNP veteran Gordon Wilson has called for the immediate relaunch of the Yes Scotland campaign, as speculation mounted that a second independence referendum could take place next year.

His intervention came as David Davis, the secretary of state for exiting the EU, suggested the legal process through which the UK would officially start its two-year Brexit negotiations would begin in early 2017. That prompted First Minister in turn to draw attention to preparations for a second plebiscite on Scotland’s place in the UK.

Wilson said: “If the Scottish Government is drafting legislation for the next decisive test of Scotland’s destiny, then the preparations for the next campaign must also be drafted.”

“We need action now. I call upon the SNP to consult with the Yes groups that performed so well in 2014 with a view to reviving a Yes Scotland campaigning organisation to mastermind the steps to bring support for independence up to 60 per cent.”

After the EU vote on June 23, Wilson appealed for a more cautious approach towards a second independence referendum, saying the SNP should not aim to hold one within the next five years.

But he appeared to change that stance yesterday, pointing out how political circumstances were changing swiftly, with the formation of the new Conservative Government and support for independence increasing.

“It is no secret that I am sceptical of the chances of victory in a premature second attempt,” he said. “But the position is remarkably dynamic. Support for independence in the aftermath of the EU referendum has risen to 55 per cent, with many former unionists switching to independence to safeguard our country’s position in the European Union.

“While still not at the critical level of 60 per cent that would guarantee victory, independence could be within reach.”

His call came as the prospect of a second independence referendum taking place next year emerged.

Asked if she is dissatisfied with the UK’s approach when formal Brexit negotiations begin – potentially early next year – the First Minister told the BBC’s Sunday Politics Scotland: “That’s why I am also, in parallel to these discussions, making sure the Scottish Parliament is making preparations to have another independence referendum if we find ourselves in that position.

“I don’t want to get too far ahead of myself just now, but of course at that point that would be an option and decision that I would have to consider.

“I will have an independence referendum if I come to a conclusion that I think that is in the interests of Scotland.”

Responding to Wilson’s remarks, an SNP spokeswoman said: “There is no doubt that many people who voted against independence in 2014 – based on assurances from the No campaign that it was this only way to protect Scotland’s EU status – are now reconsidering their position.

“The SNP Government is currently exploring every possible option to protect Scotland’s EU relationship. But if it becomes clear that the only way to do that is by becoming an independent member, then that option must be on the table.

“That is why the necessary legislation is being prepared to enable a referendum to take place if and when Parliament so decides.”

It also emerged yesterday that the SNP is considering plans to ditch its policy on an independent Scotland sharing the pound and instead to replace it with a new currency pegged to sterling.

Earlier this month, Nicholas Macpherson, the former permanent secretary to the Treasury, wrote in the Financial Times that there was a “golden opportunity” for supporters of Scottish independence to “re-appraise their economic prospectus”.

He wrote: “It is surely time... for the Scottish Government to commit to creating a Scottish pound supported by its own central bank.”