A Scottish independence referendum this year remains possible but it is “more likely” that it will happen next year, Pete Wishart, the seasoned SNP backbencher, has suggested.

The MP for Perth and North Perthshire, who marks his 20th year on the Commons green benches this year, also claimed there was “tension” at the top of the Tory Party with its upper echelons split between hawks and doves on how to approach the issues of the Scottish Parliament, independence and any future referendum.

He attacked Alister Jack for “speaking through a hole in his head” after the Scottish Secretary suggested any vote on Scotland’s future organised by Holyrood would not need to be challenged in the courts because it would be clearly illegal as Westminster held power on constitutional issues.

Last month, Michael Russell, the Scottish Government’s Constitution Secretary, announced that, in light of Boris Johnson’s repeated refusal to countenance facilitating a second referendum, the Scottish Government would seek to hold its own vote if there were a parliamentary majority for one in Edinburgh following the May poll and once the pandemic was behind Scotland.

At the end of last year Ian Blackford, the SNP leader at Westminster, insisted Indyref2 “must take place in 2021” but Nicola Sturgeon shortly afterwards suggested it would happen in the “early part” of the next Holyrood parliament ie before spring 2023.

Asked if another referendum could really happen this autumn in the wake of the Covid crisis, Mr Wishart told The Herald: “The key thing is the pandemic has to be cleared up. There are different views about how quickly or slowly that might happen. If the vaccine kicks in immediately in the spring when things have decidedly improved[it could happen] but all of that we don’t know.

“I heard something about measures continuing to be in place well into the autumn and that would scupper any chance of having a referendum this year if all the other processes go well.

“Mike was right to say if everything falls into place and all the conditions are right, there is no reason why we couldn’t have an independence referendum this year but the conventional view from all of us who have an interest in this is it’s much more likely that it will be what Nicola said: the first half of the next parliamentary term. While it’s possible this year, what’s more likely we are looking at a gate in that period.”

Asked if he was, therefore, suggesting 2022, the backbencher, who chairs the Commons Scottish Affairs Committee, said: “Yeah. We all know everybody is so excited about dates and you’re trying to draw me into suggesting a possible date but there are so many variables in this thing, it’s difficult to confine this to a specific point.”

When it was pointed out that an opinion poll had suggested not even most SNP supporters wanted a referendum in 2021, Mr Wishart stressed how there was “loads of strange stuff” in surveys just now.

As a contrast to people saying they did not want Indyref2 this year, he pointed out: “We are finding other opinion polls saying people want a process which just involves a majority at an election. You could sort of find anything in the polls just now. A lot of it is quite contradictory because people are dealing with other things; they’re focused on the pandemic or they’re not.”

Mr Wishart also claimed the Conservatives, in the face of 20 consecutive polls showing a majority for the Yes campaign, were “panicked” and “conflicted” on how to deal with the issue of another Scottish independence referendum.

“There is a tension in the upper echelons of the Conservative Party among those with an interest in the Union about which route to pursue. Is it the aggressive Unionism that we have seen over the past few years with things like the Internal Market Bill, constraining the powers of the Scottish Parliament? Or is it, as [Lord]Andrew Dunlop sort of hints at it, there has to be a much more cuddly approach, a consensual approach, listening to the Scottish Parliament and deserting some of the harder messages and trying to involve them as a partner.

“What is happening is there is a debate playing out, probably in the constitution unit in No 10 about the approach to take. That’s what’s at the heart of them not bring the [Dunlop] Report forward. What Andrew is going to present is a much more conciliatory approach to working with the Scottish Parliament and that goes against the better instincts of some of the other ones who believe in the Internal Market Bill, who want to take on the Scottish Parliament more robustly.”

Mr Wishart pointed to hawks and doves among senior Tories on the issue of the Scottish Government, Holyrood and independence with the former including the Prime Minister and Mr Jack with Michael Gove, the Cabinet Minister, among the latter and Douglas Ross, the Scottish Conservative leader, moving between the two.

“They just don’t know what to do and don’t have a clue on how to approach this now,” added the Perth MP.