A new poll suggests Scottish voters back independence over remaining in the UK – but signals warnings for the de facto referendum method.

The YouGov poll, reported by the Times, of 1,090 voters found 47% would favour independence, while 42% support staying in the union.

Support for independence has increased by 4% since a previous survey in October, while the No vote fell by three points.

Some 8% were undecided, would not vote or did not state their preference.

However, when these voters were excluded, independence support totalled 53% compared with 47% for the union.

The Supreme Court ruled last month that Holyrood cannot hold a legal referendum without the consent of Westminster.

First Minister and SNP leader Nicola Sturgeon then said the next general election will act as a “de facto referendum” – with more than 50% of the vote for pro-independence parties needed for a mandate.

But the survey shows voters could be unsure of that plan, with support for the SNP in a general election projected to fall two points to 43%.

Fifty-two per cent said they do not think a pro-independence vote majority would constitute a mandate for a referendum – with 23% of SNP supporters agreeing with this view.

Meanwhile, 39% of people said the de facto referendum would be enough to leave the UK, while 9% were not sure.

However, 51% believed the Scottish Parliament should have the power to hold the ballot, compared with 39% against and 10% undecided.

Voters were also against a 2023 referendum – 52% – with 38% in favour and 9% unsure, however 51% did say there should be a vote within the next five years.

Polling expert Professor Sir John Curtice, of Strathclyde University, said the poll was the highest pro-independence result recorded by YouGov, equalling a result last seen in August 2020.

He said: “On this evidence, just saying ‘no’ to another ballot does not look like a viable long-term strategy for maintaining public support for the union.”

His analysis puts the SNP at 46 MPs in the Commons at the next election, to be held before January 2025 – a fall of two.

It is the fourth consecutive poll on independence which has showed a lead for the Yes support, following surveys from Redfield and Wilton Strategies, Ipsos and Find Out Now.