SO is the glass half-full, or is it half-empty? The new Ipsos MORI poll is the 22nd in a row to show a pro-independence majority – but it’s also the fifth in a row to show a decline in the Yes vote.

Perhaps more importantly, it’s the third in a row to show a drop of several points.

I’d still plump for the glass half-full interpretation, though, simply because of the totally unprecedented nature of such a sustained run of Yes-majority polls. Over the years, when Yes has occasionally nudged into the lead, it’s as if there’s been an invisible force of gravity that has always dragged us back very swiftly to a No advantage.

So the fact that Yes has been continuously ahead since last June suggests that something fundamental has changed – and is testament to the electorate’s faith in Nicola Sturgeon’s handling of the ongoing crisis.

Nevertheless, there had been a hope in some quarters at the turn of the year that the completion of the Brexit transition would push the Yes vote even higher, and it now seems clear that the swing has actually been in the opposite direction.

That can perhaps be explained by the lockdown distracting the public from the harsh effects of a hard Brexit, but another factor is probably that the SNP leadership themselves have become distracted by battles with internal foes (whether real or imagined) – and have temporarily taken their eyes off the main prize.

READ MORE: Independence supported by majority of Scots, 22nd consecutive poll shows

A supplementary question in the Ipsos MORI poll finds that just over one-fifth of people who voted SNP in the 2019 Westminster election now have a less favourable view of the party due to the inquiry into the Scottish Government’s handling of the accusations against Alex Salmond.

That’s a substantial minority of votes that the SNP can’t afford to lose.

Thankfully, the worry is hypothetical for the time being. The poll suggests that the SNP remain on course to win an absolute majority of the popular vote on the Holyrood constituency ballot, and are holding steady at a remarkable 47% of the list vote.

We know from the experience of 2016 that a large lead can suddenly contract over the course of an intense campaign, so there is no room at all for complacency – but it’s fair to say that an overall majority of seats is there to be won if the campaign messaging is correctly judged.

Of huge significance is that Ipsos MORI have corroborated findings from Panelbase and Survation polls I’ve commissioned over the last year, which showed public support for a so-called Plan B if the UK Government continues its attempts to veto an independence referendum.

In the new poll, a combined total of 52% of the electorate think the SNP should either go ahead with a referendum against London’s wishes or “take the UK Government to court” to secure a legal referendum.

Respondents were also asked for their preference between the two candidates for the Scottish Labour leadership. Given that Anas Sarwar is overwhelming favourite with the bookies, the results are surprisingly tight, with Monica Lennon only three percentage points behind among the electorate as a whole and just five points adrift among Labour voters.

Ms Lennon, it must be remembered, is probably less well-known to the public than her opponent, which raises the intriguing possibility that she may be faring even better among a Labour electorate who will be far more familiar with her.

Could a surprise outcome be on the cards? Or is the current Scottish Labour membership tilted towards Starmer loyalists who will propel Mr Sarwar to a more comfortable win than the poll implies? We’ll find out very soon.