For the first time in Scottish history, the Yes side is the favourite to win a referendum on Scottish independence.

That’s polling expert Professor Sir John Curtice’s interpretation of a series of surveys showing increased support for Scottish sovereignty.

Panelbase studies published in June and July found 54% of Scots now back a Yes vote, a five-point surge since March.

Speaking on the What Scotland Thinks podcast, Curtice commented: “It does look as though there’s been another increase in support for independence. One has to say this is the longest period of time over which we’ve had support for Yes averaging ahead of support for No.”

He warned that “we are certainly not” in the territory that if a referendum was held next year the independence side would be sure of victory.

READ MORE: Support for Scottish independence skyrockets in latest Panelbase poll

But the the University of Strathclyde politics professor said: “This is the first time in Scottish polling history when one could say ‘if there were an independence referendum today, on the evidence available, the Yes side are narrow favourites'.

He added: “We do have levels of support for independence which go beyond just odd individual polls giving a dramatic results – such as the famous, or in some people’s views infamous, YouGov survey shortly before the 2014 referendum which had Yes at 51%.

“Here we’re getting consistent evidence across a sequence of polls all pointing in the same direction and at that point one has to sit up and take notice.”

Last year, the increase in support for independence was coming entirely form Remain voters, Curtice said, presumably because of Brexit. But the professor added this was offset largely by a number of pro-Brexit voters who switched from Yes to No.

This year, however, the surge in support for independence is different.

READ MORE: Vast majority of Labour MPs expect Scotland to be independent by 2030

“The interesting thing about the more recent increase in support is that it is in evidence amongst Leave voters and amongst Remain voters,” Curtice explained.

“The last three months has seen devolution become more visible, across the whole of the UK, than it ever previously has been. This has been a period when all the crucial decisions about the running of the health service, and the measures that were introduced to try and protect public health .. these were being taken by Edinburgh.

He acknowledged such decisions are made "within a framework set by the UK Government", but noted as the crisis has unfolded the decisions have increasingly been diverging from London.

Curtice stated: “All the lives of everyone in Scotland have been affected by the devolved government in a way that they’ve frankly not been in the previous 21 years of devolution.”

The polling expert also pointed out that Nicola Sturgeon is perceived – by both Yes and No voters and Leave and Remain voters – to have handled the crisis far more competently than Boris Johnson.

In this sense, Curtice says the pandemic has bolstered pro-Yes arguments that Scotland would be able to govern itself more effectively as an independent nation.

“It does look as though the handling of the coronavirus has eroded just that bit further the level of support for the Union.” He added: “We do now seem to be looking at a modest, but probably clear majority in favour of independence.”