UNIONISTS should have "stuck the boot in" in after winning the 2014 referendum, Ruth Davidson says.

In an interview in the Sunday Times, the former Scottish Tory leader says the No side made a "huge strategic error" by trying to prove they were "bigger people" than Yes campaigners.

That's despite David Cameron's next-day decision to bring in English votes for English laws (EVEL) and to green light the Brexit referendum which will lead to Scotland's unwilling exit from the European Union.

Davidson, who will soon exit the Scottish Parliament, says independence is not "inevitable".

And she says strategists are working on a "new Union story" to sell to the Scottish public.

The Edinburgh Central MSP said: "Mistakes have been made and one of those mistakes was not sticking the boot in after the 2014 referendum. We wanted the country to come back together and we were, if you like, interested in showing ourselves to be bigger people than them.

"That was, morally, the right thing to do but tactically it was a mistake. A huge strategic error, in fact.

"I'm not as depressed as a number of unionists seem to be right now. That's not because I'm complacent. I can read a poll as well as anyone and see long-term trends in data.

"However, the fundamental strengths of working across the UK remain. So too do the fundamental weaknesses of pro-indy positions on key economic elements such as currency, central bank.

"That's not enough and we know that and work is going on to develop a new Union story.

"But I do disagree with those who think the SNP trajectory is inevitable ever upwards."

The SNP and Scottish Greens have each recorded election successes since 2014, with the Greens now a bigger presence in Holyrood than the LibDems and the SNP winning a historic third term in office, as well as a Westminster surge that took them to 56 seats just months after indyref.

Yes voices have called for indyref2 as a result of the "material change in circumstances" brought about by the Brexit referendum.

And polling expert Sir John Curtice says independence would now be the likely outcome if the poll is repeated.

Last month he said Yes would be "narrow favourites” to win due to "consistent evidence across a sequence of polls all pointing in the same direction". He said: "And at that point, one has to sit up and take notice."

In fresh comments about the importance of the economic question, he stated: "As the Prime Minister himself acknowledged, unionists need to say more than that Scotland cannot afford independence.

"They need to make a positive case for the union.

"That implies doing more than trumpeting the actions of the UK Government north of the border, but rather demonstrating how devolution would be used to deliver for Scotland.

The political divisions within the unionist camp meant that argument was rarely to be heard before the 2014 referendum, but articulating it would now appear to be crucial."

Visiting Scotland last week for the first time since the general election, Boris Johnson called the Union a "fantastically strong institution" which has "helped our country through thick and thin".

Restating his opposition to a second referendum on Scotland's future, he said: "It's very very valuable in terms of the support we've been able to give to everybody throughout all corners of the UK.

"We had a referendum on breaking up the union a few years ago, I think only six years ago, that is not a generation by any computation."

That's despite plans for a post-Brexit UK "internal market" which, according to the Scottish Greens "calls into question the very notion of devolution itself".

Ministers in Edinburgh fear the new regime could lead to lower standards in food safety and environmental protections being imposed in Scotland and Green co-convenor Patrick Harvie said the move shows there is "absolutely no respect" for devolved parliaments.

Meanwhile, Keith Brown MSP said: "The problem for Ruth Davidson is that Westminster very much has been 'sticking the boot in' since the 2014 referendum result.

"Before that vote, we were told that the UK was a partnership of equals – but since that vote, the Tories have dragged us out of the EU against our will, are trampling all over the powers of the Scottish Parliament and are putting our NHS and key Scottish industries under threat in a desperate bid to secure trade deals.

"Majority support for an independence referendum is now the consistent position in poll after poll and it’s no wonder the Tories are in panic mode.

"An ever-increasing number of people in Scotland now agree that the only way to properly protect Scotland's interests is by becoming an independent country."