INDEPENDENCE supporters are frustrated and “turning in on themselves” because of a lack of leadership on a second referendum, the former deputy leader of the SNP has admitted.

Jim Sillars said there was a risk of a damaging split in the Yes movement over when to ask voters again about leaving the UK, and the issue required clear thinking, not online “bile”.

The Yes movement is divided over whether to use the "cast iron" mandate the SNP says it has to push for a referendum before the 2021 Holyrood election, or play a longer game.

After calling a referendum in March 2017, then announcing a "reset" after losing a third of her MSPs in June's election, the First Minister is due to update MSPs on the "precise timescale for offering people a choice over the country’s future” in the autumn.

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In a newspaper article, Ms Sillars said a “coherent Yes organisation” was needed to build “rock solid” support of 60 per cent for at least six months before attempting another vote.

He said: “These are frustrating times for Yes people, and turning in on themselves is a natural political phenomenon that requires some sensible thinking and handling before it becomes damaging.

"Those of us who have been a long, long time in the independence movement have seen this kind of frustration boil over several times as people fall out, not about the objective, but how to get there.

“The 2014 campaign gave us a foundation of 45 per cent upon which to build, but to raise that to a level of victory demands a high level of maturity, wisdom, and organisation so far missing."

Ms Sillars was responding to a recent wave of online attacks against SNP MP Pete Wishart from fellow Nationalists, after he called for a pragmatic timescale on a new vote.

Sillars: I'd rather abstain on independence than vote Yes to EU return

After seeing the Tories cut his majority in Perth & North Perthshire cut from almost 10,000 to just 21 last year, Mr Wishart admitted many voters were “weary of big constitutional choices”.

He said it would be wrong to rush into a second referendum before there was clear public support for one, as a second defeat would set the independence cause back “decades”.

Mr Wishart’s comments led to him being attacked by his own side on Twitter as a Unionist “poster boy” and “Etonian boot licker”, and as settled in a cosy Westminster lifestyle.

Mr Wishart, who once called No supporters “nawbags”, demanded more respect, and said “shouting people down, name calling and misrepresenting people’s views” were unhelpful.

Pete Wishart appeals for respect and unity amid Yes movement split

Mr Sillars said people should “lay off” Mr Wishart, and said his independence credentials were "unimpeachable”.

He wrote: “Pete Wishart was in the SNP during those times, when it was difficult to keep the faith. For anyone to believe this man would sell the jerseys now does their mental condition a disfavour, not his.

"To stop a split developing and verbal bile via social media becoming the language of discourse, there is a need for some rational thinking with consideration of where Scotland stands at present, assessment of issues that will determine the new policy positions we shall need, and an honest admission of what the present Yes movement is and is not, and why that is a dangerous weakness.

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The Scotland that was in 2014, inside the EU, is not the Scotland that is going to be with Brexit; and that will not be clear until the Brexit treaty is signed, and studied in detail.

"Until that is done, we shall not have any definitive policy on a future Scotland on which to fight an independence referendum."

Mr Sillars was a prominent Brexit supporter.

His latest comments have already seen him condemned by some Yes supporters as putting leaving Europe ahead of leaving the UK.

Ex-SNP deputy leader Jim Sillars calls on independence movement to sever ‘deadly tie’ with former party

Scottish Conservative chief whip Maurice Golden said: "The splits within the Yes movement are becoming deeper by the day. This is yet another intervention that will cause Nicola Sturgeon a major headache.

"Both she and Jim Sillars realise the people of Scotland cannot be respected and the rabid nationalist movement appeased at the same time. Repeated polling has made it very clear voters are absolutely opposed to another unwanted and divisive referendum campaign."

An SNP spokesperson added: "These are hugely ironic comments coming from a Tory party which has no mandate in Scotland but whose politicians now arrogantly think they can do whatever they want and get away with it.

"Support for independence remains at historically high levels, and backing for Scotland taking its own decisions is only likely to grow further – but the country’s future belongs to the people, not to the Tories or any political party."