Nicola Sturgeon has said she will shortly outline the potential circumstances for another independence referendum - but what would it take to convince a still "exhausted" Scottish public to do it all over again?

The 2014 referendum was held on the basis that people supported a wide-ranging SNP manifesto that included a vote on independence, but also pledged low taxes, better health, more police and more jobs.

The SNP administration's approval ratings remain high after eight years, but can a mandate for another referendum be uncoupled from all of the other popular goodies the SNP has to offer?

If the SNP wants another referendum before a majority of Scots are ready, would voters risk throwing the government baby out with the nationalist bathwater?

Professor Charlie Jeffery, senior vice-principal of Edinburgh University and co-ordinator of the Economic and Social Research Council's Future of the UK and Scotland programme, said there are very few obvious triggers for another referendum on the horizon.

A vote to leave the European Union against majority opinion in Scotland is a conceivable outcome of the looming EU vote and the "easiest and quickest route" to another Scottish independence referendum, according to Mr Jeffery.

Other divisive votes are expected at Westminster including the renewal of Trident, the Scotland Bill and military action in Syria.

The SNP currently opposes all of these but they are unlikely to have the same "elemental significance" to spark a re-match, Mr Jeffery said.

And even if the SNP does secure another referendum mandate, could it sustain the momentum that has pushed support for independence to 53% in recent polls once "Project Fear" gets back in gear?

The Yes campaign failed to present a "credible answer" on currency and the management of volatile oil revenues, and failed to convince many businesses of the case for independence, according to Mr Jeffery.

He said: "The referendum campaign was exhausting.

"It was exhausting for the participants, and it was exhausting for voters to have such a long period discussing the issue.

"It would be testing the patience of the voters to go back to that too soon if the issue was not really a fundamental one."

Mr Jeffery describes the current polls as "a kind of mood thing which doesn't necessarily signal the outcome of any future referenda".

He added: "You would see all of those other arguments enter the fray on which the Yes side didn't have strong enough arguments around various economic themes.

"But it probably underlines a point that people didn't vote No because they were enthusiastic about the British state - they voted No because they weren't convinced enough by independence and could be convinced to vote Yes in other circumstances.

"It was clear the Yes campaign had real weaknesses, and the biggest one was around currency which is very immediate for people thinking about the money in their pockets.

"I don't think the Yes side was prepared for that kind of unambiguous statement from George Osborne (rejecting a currency union).

"There wasn't really a credible answer to that, and if a future Yes campaign is going to win it's going to have to be on that issue.

"Also, some of the wider issues about business confidence were really important, especially in that last phase of the campaign when a number of major business organisations were saying: 'We might not stick around.'

"I suspect also, even though the SNP was saying oil was a bonus and not the basis of the economy, if the oil industry is in the situation it is now and the global oil price remains where it is now that creates an additional uncertainty.

"So there are things the Yes campaign could do to address its weaknesses, but there are also some global things that in order to win they have got to be in the right place in the right time.

"In an EU referendum it would be hard to envisage a vote in Scotland to leave, but it's conceivable that there could be a vote in England to leave.

"I suspect that is the easiest and quickest route to another referendum.

"Others talk about Trident, but I'm less sure that that has the deeper elemental significance."

He added: "We will see lots of jockeying around the Scotland Bill, which of course needs the consent of the Scottish Parliament, and some of that may well be in national conversation about the Scotland Bill versus English votes for English laws, but I doubt whether they are issues that would have sufficient resonance."

He continued: "I doubt that Syria will be that big a trigger.

"It would be something that would certainly be presented as a difference in opinion here in Scotland, and there in England, but I'm not sure there is such stark evidence in public opinion if you look at the data that is available.

"It would certainly continue that climate that Westminster is about another place, that is not quite what we are here.

"It would solidify the SNP's anti-Westminster pro-independence feeling, but I suspect it will not be elemental enough to risk another referendum."