THE outcome of the race to become the next SNP leader is uncertain as the contest enters its final days, with a “lack of evidence” on what party members are thinking, a polling expert has said.

The ballot to decide whether Kate Forbes, Ash Regan or Humza Yousaf will win closes at noon on March 27, with the result due to be announced on the same day.

Mark Diffley, founder and director at The Diffley Partnership, pointed out there has only been one poll of SNP members carried out so far.

“There is a couple of issues with that – one is that it is about three weeks old now, so it was done quite near the beginning of the campaign,” he said.

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“It had about a third of members saying they didn’t know, so I suspect that is a lot less now. By now all will have voted or be pretty sure they know who they are going to vote for.

“Of course it also didn’t ask about second preferences, it just asked who they were going to vote for – but the second preference is possibly going to be quite significant.

“Unless we have really read this wrong, I suspect Ash Regan will come third, which means if one of the other two candidates doesn’t get 50% in the first round, then Ash’s supporters' second choices will become quite significant.

“Let’s say she gets 10% and the other two get 45% each in the first round – then where her second choices go becomes absolutely key to who is going to win.”

Diffley said there was a difference between the contenders with Yousaf the choice for “continuity”, while Forbes and Regan the “rip it up and change” candidates.

“It is fair to say there is an absolutely clear dividing line between the three and it certainly doesn’t fall into with other parties’ previous contests where it is all a much of a muchness,” he said.

“There is definitely a clear choice for people to make, but there is a bit of a lack of evidence of what members are actually thinking.”

The poll of SNP members, carried out by Savanta, was published on March 3 and 31% of respondents said they supported Yousaf, with Forbes in second place on 25% and 11% backing Regan.

But nearly a third – 32% – did not know who they would opt for.

The latest poll of the public, carried out by YouGov, found Forbes was most popular with 27% saying she would be a good first minister, compared to 22% for Yousaf and 15% for Regan.

Diffley said membership polling was “nigh on impossible to do” without having a large number of SNP members on an online panel or access to party membership lists.

He added: “So the polling of the general public has acted as a kind of an alternative way of at least trying to see what the broader public are thinking in the absence of a lot of membership polling.

“The general public polling does have a purpose as I think we saw this during the hustings and the TV debates, from Kate in particular.

“Humza was clearly pitching at members, everything was pitched at members, from his point of view trying to say what members would like whether that was around independence, process, challenging the section 35 order that kind of stuff.

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“Whereas I think what Kate was doing was using the general public polling – most of which was more favourable to her than the other two candidates – and talking to members.

“But she was saying what you need to think about here is who is electable, who is going to actually once we are through this contest and back into the big wide world, which of us is more likely to succeed in continuing to be the party of government and so on.

“So in a sense they were both playing to the SNP membership but in slightly different ways.”

Dr Catherine Happer, director of Glasgow University Media Group, said the SNP leadership debate is a reflection of the contemporary media and political environment which it is taking place in.

“[It is a] highly adversarial, divisive and often tribal social media sphere, and a UK political and mainstream culture strategically organised around ‘culture war’ issues led by the Conservative government in Westminster,” she said.

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“Kate Forbes offered journalists news-bait in the form of an early interview in which she perhaps unexpectedly emphasised that at least hypothetically she wouldn’t separate the personal from the political such as on equal marriage.

“This early statement set much of the tone of the early coverage on mainstream media, and was the axis around which people started to position themselves on social media in which ‘taking sides’ is a key part of engagement and profiling.”

Happer said another feature of the coverage had been the question of competence, with Yousaf as the "continuity" candidate particularly coming under attack from his rivals over his record in key ministerial roles.

She added: “Whilst these criticisms have been very personalised and abrasive, party members attacking each other are not unusual in a party leadership contest.

“In the Tory leadership contest in 2019 for example, Rory Stewart who was running against Boris Johnson said the party needed to move away from 'great leader macho posturing'.

“In the end the attacks didn’t hurt Johnson too much. Parties tend to consolidate once they are in power.”