Both leaders’ offices have confirmed that on Mr Legault’s visit to Scotland last week, no attempt was made to set up a meeting with Ms Sturgeon. This is despite the two governments having previously enjoyed cordial relations in the spirit of seeking independence for their territories.
Daniel Béland, James McGill professor in the department of political science at McGill University in Montreal, said Mr Legault’s status as a former long-term supporter of Quebec independence, but now – despite remaining a nationalist – no longer being in support of sovereignty, could make Ms Sturgeon nervous about parallels being drawn between Canada and Scotland.
He said the situation playing out in Quebec – where the party in power are former supporters of independence who set up their own pro-nationalist parties, but no longer support an independence referendum – could be a “nightmare scenario” for Ms Sturgeon.
The Scottish Government has pledged to hold a new referendum on independence by the end of 2023.
Mr Legault has been the leader of the nationalist party Coalition Avenir Québec (CAQ) since it was founded in 2011 – and the first premier who is not a member of the Quebec Liberal Party or the Parti Québécois (PQ) since the 1970s, despite having previously been a Cabinet minister in the pro-separatist government.
The CAQ party was one of a number formed after various high-profile names splintered from the main independence party, Parti Quebecois, in the early 2010s, following an unsuccessful second independence referendum in the 1990s.
Prof Béland said: "It is significant because there have been strong ties between Quebec and Scotland in terms of diplomacy and that in the past, Quebec premiers have met with Scottish officials.
"It is strange that they did not meet because Legault spent quite a bit of time in Scotland, he was there for several days.”
Prof Béland warned a further splintering of the SNP, away from support for a referendum, as has happened in Quebec, could be a “nightmare scenario” for the party.
Former first minister Alex Salmond set up his own pro-independence party, Alba, before the Holyrood election in May, taking with him a number of former MSPs.
Prof Béland said: “It could be a nightmare scenario that someone from the SNP decides to leave and says ‘we support autonomy for Scotland, but not independence’, because that is what Legault is doing.
"For Sturgeon, [meeting Mr Legault] could be a problem. It’s not the best match.”
Prof Béland said that, equally, the Quebec administration could be nervous of potential independence in Scotland.
He said: “It might be a problem because it might create a revival of the sovereign based movement in Quebec. And he [Mr Legault] has jumped off that boat long time ago.
"He no longer supports independence. He is a strong nationalist, but he rejects the idea of a referendum on sovereignty.
"I think it's a bit awkward. So if he was seen in Scotland supporting the independence of Scotland implicitly or otherwise, that might cause some some tensions within his coalition.
"There are still some people who believe deep inside he is still a sovereignist. He is not just the premier of Quebec, he is a former sovereignist who rejects that now.”
During his time in Glasgow, Mr Legault met with several dignitaries, including Prince Charles, former US Secretary of State John Kerry, and US president Joe Biden's climate advisor Gina McCarthy.
John Curtice, professor of politics at the University of Strathclyde, pointed out Ms Sturgeon was more likely to have wanted to court heads of national governments, rather than those in charge of provinces and smaller states, like Mr Legault.
He said: “Perhaps Nicola Sturgeon is not too upset not to be seen to be photographed with the premier of a nationalist movement that has so far failed and which has not really demonstrated much in the way of likelihood of success ever since it failed a second referendum – a topic on which she, at least, is currently determined to try and embark.”
Prof Curtice added: “Clearly the central issue of all of this is that no room was given to her to speak at the main [COP26] conference and that she has supplemented that by spending her time going around this enormous jamboree, and talking to a lot of people, including people who are heads of national governments.
"It was a photo opportunity and a diplomatic opportunity. At the end of the day, what she is concerned about most of all is what the premier of Canada thinks, rather than what the premier of Quebec thinks.
"One of her objectives is to create an independence that the rest of the world will be willing to recognise, so it is what the heads of national government say that matters. Who knows if she’s been able to do that on this occasion to be able to do some quiet diplomacy in that direction.”
The Scottish Government acknowledged that no bilateral meeting had been sought between the First Minister and the Premier of Quebec – from either party.
A spokesperson said: “The Scottish Government is actively engaged with Canada and ministers met with environmental ministers from three Canadian provinces, including Quebec, to discuss climate change.”
Ewan Sauves, press spokesman for the Premier of Quebec, said there had been no request for a meeting with Ms Sturgeon.
He said: “As is customary, we have notified the UK and Scotland of our arrival for COP 26, but the Minister of International Relations and of La Francophonie has not requested a meeting.”
He did not specify why no request was made.