People feeling they could be better off in an independent Scotland may tip the scales after poll rise, writes Ian Swanson.
The SNP was given a conference boost at the weekend with a new poll showing 50 per cent of Scots are now in favour independence.
Nicola Sturgeon has said she will formally ask Westminster within weeks to transfer the power to call a referendum to Holyrood and she wants to hold the vote next year.
Amid the chaos and confusion of Brexit and the possibility of Boris Johnson winning an election, handing him five years in Downing Street, it is perhaps no surprise that many in Scotland see the prospect of going it alone as more attractive.
Studies have shown that leaving the EU, however it is done, will cause serious economic damage to Scotland and the UK.
So even if the EU summit on Thursday and Friday this week leads to a deal which Mr Johnson can sell to MPs and a no-deal Brexit is averted, it is still bad news.
In the circumstances, the surprise might be that there are not more Scots flocking to the independence option.
If voters are not willing to break with the UK when Brexit threatens to cost jobs and leave everyone poorer, when will they be?
It may be the idea of yet more constitutional upheaval after the Brexit experience is enough to persuade people to stick with the status quo.
Or perhaps fears over the possibility of a hard border between Scotland and England gives cause to hesitate.
The weekend poll by Panelbase was the latest in a series of surveys to show growing support for independence after a long spell when opinion seemed not to have shifted since the 2014 referendum result of 45 per cent Yes, 55 per cent No.
There was a time when Ms Sturgeon was said to want sustained 60 per cent support in the polls for several months before she would call a new referendum. The last thing the SNP wants is to hold another vote and lose again.
She seems more inclined now to go for it as soon as she gets the chance. But Mr Johnson has insisted he will not grant the necessary Section 30 order to allow Holyrood to call the referendum – even if the SNP and their pro-independence allies win a mandate at the next Scottish Parliament elections.
Labour is more equivocal, not ruling out a new referendum but saying it will not be a priority if they win power.
Ms Sturgeon has made clear that the SNP will not support a minority Labour government unless it recognises Scotland’s right to determine its own future.
But she has wisely rejected calls from within her party for a “Plan B” if Westminster remains stubborn in refusing a fresh vote.
Reverting to the pre-devolution policy of claiming that winning a majority of Scottish seats in the Commons as a mandate to start independence negotiations is not a credible approach now. Holding a Catalonia-style referendum not recognised by the UK would lead to all sorts of problems.
Having held one referendum, the Yes campaign can only win by following the same path again and hoping for a different result.
Another finding in the weekend poll may hold the key. Around 45 per cent said Scotland would be better off economically as an independent country within the EU than remaining in the UK after Brexit, while 35 per cent disagreed.
If independence is now seen as the way to a more prosperous future, that really could be a winning argument.