ALEX Salmond has dismissed "fanciful" claims from former cabinet minister Alex Neil that nearly 40 per cent of the SNP’s 120,000-strong membership supports Brexit and that there is widespread support for Leave among the party's MSPs.

Salmond spoke out after Neil's shock admission that he voted to Leave on June 23 - the biggest act of internal dissent at Holyrood faced by the party' in its nine years in power.

Although an estimated 36 per cent of SNP 'voters' opted to leave, the argument between Salmond and Neill centres on how 'members' of the party chose to cast their ballot.

Last night, Neil risked stoking the tensions further as he warned the party leadership to “tread warily” or risk alienating independence supporters who want to stay outside the EU.

In remarks that will add to the growing internal pressure on Nicola Sturgeon’s flagship strategy for a second independence referendum which is based on Scottish opposition to Brexit, Neil said there was “no doubt that a significant minority” in the party share his Eurosceptic views

He also stood by claims that there are other party colleagues at Holyrood who hold the same position, stating: “I’m not the only SNP MSP out of the 63”.

However, Salmond who brought his one time party rival Neil into his government in 2009, also rejected tabloid claims that half a dozen of the party’s MSPs shared the former health secretary's pro-Brexit stance.

Salmond, in a swipe at Neil also said that the Airdrie and Shotts MSP's view “can’t be that deeply held” after the former minister revealed he had only decided to back Brexit in the final stage of the EU referendum campaign.

Salmond also sought to play down Neil’s claims, saying that there was scant support for leaving the EU on the SNP benches at Holyrood, adding it was “nothing like” that reported by parts of the media.

The former First Minister said: "Alex's suggestion that there are lots of SNP members with this view is fanciful.

"I'm not sure how strongly he holds these views if his views on Europe were determined by George Osborne. They can't be that deeply held.

"The [media] reports say about half a dozen MSPs agree with him. I don't think it's anything like that. I don't think that's the case as there is a consensus within the SNP on Europe."

Meanwhile, the SNP’s Europe minister Alasdair Allan, responded to Neil’s intervention, by saying “I’m strongly in favour of Europe”, while Scotland's Brexit minister Mike Russell refused to comment on the remarks.

Employment minister Jamie Hepburn, who used to work for Neil, refused to say how he voted on June 23, just referring the Sunday Herald to the SNP press office.

However, speaking to the Sunday Herald, Neil insisted he was not a lone voice for Brexit within the senior ranks of the SNP.

Neil said: "I'm going by what some colleagues said to me in the time since. I'm not the only SNP MSP out of the 63 and there are also a lot of SNP supporters with that view.

"There's no doubt that there's a significant minority of activists in the SNP who have concerns that the case for independence is tied into the EU."

When asked, what percentage of the party he thought supported Brexit, Neil cited the 38 per cent of Scots voters who cast their ballot for Leave on 23 June and said there was likely to be a similar level of support within members of the party.

He said: "The SNP has over 120,000 members and you would think that they reflect Scotland generally. You could extrapolate that number in terms of the party members with concerns."

Neil said that if the SNP continued to insist on an independent Scotland rejoining the EU it could badly damage the case for independence and lead to a second referendum defeat.

He said the SNP had to “de-couple” the issue of independence and EU membership as he warned that there was a chance an independent Scotland would face borders and customs checks with the EU, a proposition Scots would be less likely to vote for.

He said “nothing should be off the table” and that the SNP had to “reopen the debate” on Europe after decades of being a pro-EU party.

Neil added: "Most people who know me say that it's not a big surprise that I voted Leave. I've never hidden the fact that there are many aspects of the EU that worry me, but the tipping point in the referendum campaign was the scaremongering of George Osborne and David Cameron. We've got to de-couple the issue of independence.

"Otherwise there is a risk we might not maximise the independence vote and it will be difficult to win an independence referendum. The Brexit referendum changed things and we've got to tread warily."

In a sign of the confusion caused by the row, SNP president Ian Hudghton, a Scottish MEP said he “wouldn’t know” and that it was a "matter for individuals" when asked whether Neil was correct about the level of support for Brexit in the party.

However, another senior SNP figure, Moray MSP Richard Lochhead, who was rural affairs, food and environment secretary under Salmond and Sturgeon, said "clearly I voted to Remain", but added that he had sympathy for the fishing and farming sectors where there was "failed policy" from the EU.