Professor John Curtis, of Strathclyde University, said the SNP, after 15 years in government, remained the dominant political force in Scotland and that the future of the Union looked insecure.
A YouGov poll released on Wednesday night put Nicola Sturgeon’s party on course to win 49 MPs at the next Westminster election – one more than it won in 2019.
But the survey, carried out for The Times, suggested the Tories would be eliminated north of the Border, with the party expected to return zero MPs on just 12% of the vote, as happened in the 1997 Labour landslide.
Labour can expect to win seven seats – up from just one currently – on 31% of the vote, according to the poll.
Prof. Curtice, writing in The Times, said the recovery of Scottish Labour came not at the expense of the SNP but rather as a result of the Unionist vote ditching the Conservatives.
He suggested this was likely because of “recent events at Westminster”, which included the Chancellor nearly triggering a financial crisis because of reckless tax cuts and a vicious leadership challenge caused by the implosion of Boris Johnson’s government.
The SNP also enjoyed steady support because of voters’ attitudes to the “constitutional question,” he added.
Curtice said: “Contrary to what some have anticipated, there is no sign of voters switching from SNP to Labour now that there seems to be a serious prospect of a Labour administration at Westminster.
“Not that the SNP’s prospects are wholly unaffected by the change in the relative strength of its two principal unionist opponents. The party could find itself losing half a dozen seats to Labour.
“However, these losses would likely be compensated by picking up all six seats the Conservatives currently hold. The party’s dominance of Scotland’s representation at Westminster would be left intact.”
He added: “SNP support has been so little affected by the Westminster drama of the past fortnight because it is primarily shaped by people’s attitudes to the constitutional question.
“At 76%, the proportion of 2014 Yes supporters who would vote SNP is unchanged from May.”