AN SNP MP has urged Yes supporters to “take a break” this summer as the debate over the prospect of a second vote on Scottish independence intensifies.

Ronnie Cowan, who helped lead a two-year campaign in Inverclyde ahead of the September 2014 vote, spoke out as grassroots activists stepped up plans to persuade a majority of people north of the border to back independence in the likely event of a second referendum.

Opinion polls carried out last month in the wake of the European Union referendum, in which the UK voted to leave while Scotland voted overwhelmingly to remain in the EU, suggested support for independence had increased.

However, Cowan referred to comments made last week by the former SNP leader Gordon Wilson who said he was “sceptical of the chances of victory in a premature second attempt” and that it would be a mistake for a campaign to formally start with no timescale to work to.

“Campaigners have given a massive amount of time and energy to previous referendum and elections,” he told The National.

“Many have worked for the best part of four years without a break.

“I think it is wrong to take for granted the sacrifice many people have made and I urge them all to take a break, rest up and keep informed.”

He added: “I know casual groups still meet up and chat and are already deciding how to run the next campaign better. Once we have a clearer picture of Scotland’s future within the UK and the new prime minister has started to make her mark, then we shall be in a better position to decide when to have a referendum and how to run it.”

Independence supporters have been using social media to publicise a pro-independence march to take place in Glasgow next Saturday.

And yesterday, the Sunday Herald reported that the grassroots Yes movement is set to take the lead in the campaign over the following weeks, after the SNP postponed its own “summer initiative” in light of the Brexit vote.

SNP officials last week insisted the push would be rolled out “within weeks”, but a meeting of the party’s ruling National Executive Committee in Glasgow on Saturday heard there was still no definite start date and limited detail on what it would involve.

Sources told the paper Brexit had forced a full-scale rethink of the party’s message to voters.

But candidates for the SNP depute leadership post have been keen to underline a new push towards independence.

Unveiling his campaign last week, frontrunner Angus Robertson, the party’s Westminster leader, argued Scotland is “on the brink of independence”, while fellow MP and rival candidate Tommy Sheppard has stressed he is confident the battle for independence can be won.

He has underlined the importance of reaching out to No voters.

Meanwhile Alyn Smith, a third candidate for the job, indicated at his launch last week that he believed European leaders had shifted their sympathies towards finding ways for Scotland to remain in the EU when the UK left.