DAVID Mundell has hit out at the SNP’s “demonising” of Boris Johnson, who has announced his bid to run for the Conservative leadership once Theresa May steps down this summer.

The former Foreign Secretary told a business event in Manchester: "I'm going to go for it. Of course, I'm going to go for it," adding: "I don't think that is any particular secret to anybody."

The Scottish Secretary stressed how he would not be voting for Mr Johnson in the forthcoming leadership contest, indeed he has previously been critical of him, yet nonetheless, Mr Mundell decried his colleague’s treatment at the hands of his Nationalist critics.

READ MORE: Boris Johnson 'complete and utter charlatan,' says Nicola Sturgeon, who, as PM, would boost independence cause 

Earlier this year, Ian Blackford denounced him while he was still in office as a “bumbling Foreign Secretary who is making the UK a laughing stock”.

Last autumn, Nicola Sturgeon told the SNP conference that a "political system that throws up Jacob Rees-Mogg and Boris Johnson as contenders for Prime Minister has gone very badly wrong”.

More recently, the First Minister, again commenting on the prospect of a Johnson premiership, said if it happened, then support for Scottish independence would “sky-rocket”.

Mr Mundell told The Herald: “That’s the sort of thing she says; that’s the sort of language she uses. I’m not accepting this Nationalist demonising of him...”

Yet, there will be a strong move by the Scottish Tories to stop Mr Johnson’s bid for the Conservative crown.

Last autumn at the Tory conference, MPs launched what they indelicately dubbed “Operation Arse” to stop the former Secretary of State getting into the final run-off between two candidates, which goes to the party’s grassroots to choose the winner.

A senior Conservative noted at the time: “We called it that so we’d all be clear who we were talking about.”

At the same conference, Mr Mundell claimed Mr Johnson was “not an asset” to the party in Scotland and accused him of being "focused on his own self-interest and not on the interests of our country" after he attacked the PM’s Brexit plan.

READ MORE: Cross-party Brexit talks close to collapse, sources suggest 

Yet The Herald has been told that the Scottish Secretary has not ruled himself out of serving in a Johnson Cabinet.

With the prospect of a summer leadership contest now looming, Scottish Tories have continued to express alarm at the possibility that Mr Johnson might win by suggesting such an outcome would “gift-wrap independence” for Ms Sturgeon and that it would “kill off” any chance that Ruth Davidson, the Scottish Conservative leader, might have in becoming FM at the 2021 Holyrood election.

Responding to Mr Johnson’s announcement Alex Cole-Hamilton, the Scottish Liberal Democrat MSP, said: “Britain faces so many questions at this moment in history; the answer to none of them is Boris Johnson.

“Even the Scottish Conservatives have banned him from Scotland; so, as Prime Minister of the United Kingdom he will be a fat load of use.”

Mr Johnson was in Aberdeen earlier this month where he spoke at a fund-raising event for the local Conservative associations.

He is now among what has been dubbed a “Conservative cavalry charge” as no fewer than nine Tories have their eyes on the leadership crown. They also include Michael Gove, Jeremy Hunt, Sajid Javid, Amber Rudd, Dominic Raab, Rory Stewart, Liz Truss and Esther McVey.

The Herald has been told by party sources that Mr Gove, the Environment Secretary and leading Brexiteer, fancies his chances and already has 50 to 60 backers among Tory MPs.