The environment secretary was one of ten Tory MP confirmed as candidates for the Conservative leadership yesterday, the most crowded field in the party’s modern history.

Leadership rivals will face off in two hustings debates at Westminster today and tomorrow, before the first ballot of Tory MPs on Thursday that will eliminate those that fail to get at least 16 votes from their peers.

Mr Gove rejected suggestions that his challenge was finished thanks to the damaging revelation that he had taken cocaine before entering politics, at the same time as writing newspaper columns condemning middle-class drug use.

The ten contenders in the Conservative leadership race (top row, left to right) Boris Johnson, Dominic Raab, Jeremy Hunt, Rory Stewart and Mark Harper, (bottom row, left to right) Esther McVey, Matt Hancock, Andrea Leadsom, Michael Gove, and Sajid Javid.

Instead, he said he was “sure” he would make it to the last stage of the contest, where the final two candidates will be put to a ballot of party members, and mocked the frontrunner Boris Johnson, telling him: “Don’t pull out.”

Mr Johnson abandoned a previous leadership bid in 2016 after Mr Gove quit his campaign to launch his own failed attempt to reach 10 Downing Street.

At his campaign launch yesterday, Mr Gove, who has the most support among Scottish Tory MPs of any candidate, denied applying a double standard on drug use while serving as justice secretary.

“One of the consequences of having had the chance to reflect on my mistakes, is that when I was justice secretary I was determined to ensure that those people who had fallen into the net of the criminal justice system were given all the support, the help and the care they needed in order to achieve redemption and to enjoy a second chance,” he said.

He vowed not quit the race, saying: “I’m in it to win it ... every time I’ve been given a job I’ve been told it’s impossible and have delivered.”

In a pointed challenge to his former friend, Mr Gove added: “If I get through, which I’m sure I will actually to the final two against Mr Johnson, this is what I will say to him.

“Mr Johnson, whatever you do, don’t pull out.”

He said the “deeply personal” choice to put friendships and family ties on the line by leading the Brexit campaign in 2016 was a sign of bravery, and in a veiled attack on Mr Johnson, called on other candidates to get out of their “bunker”.

He also said the UK needed a “serious” leader who had been “tested in the heat of battle”, adding: “I don’t want a situation where we have Jeremy Corbyn in Downing Street, propped up by Nicola Sturgeon, breaking up our United Kingdom.”

He set out a package of measures he said would help secure the Union that will appeal to his Scottish Tory backers, including bypassing Holyrood with new funds to invest directly in Scotland, and creating a ‘Union unit’ at the heart of government to test policies and make sure they work for all nations of the UK.

Four other leadership contenders launched their campaigns yesterday, with many seeking to define themselves in opposition to Mr Johnson. Former Brexit secretary Dominic Raab said Brexit could not be delivered through “bluff and bluster”, and said he was willing to suspend Parliament to take the UK out of the EU without a negotiated deal. “We’ve been humiliated as a country in these talks with the EU,” Mr Raab claimed. But the option of proroguing Parliament was attacked in strong terms by health secretary Matt Hancock, who invoked the memory of D-Day troops, saying it “goes against everything those men who fought their way up those beaches died for”.

Mr Hancock won a significant endorsement last night with the backing of David Lidington, effective deputy to Theresa May.

For all the latest Scottish news, sport and features click here, or head to our Facebook, Twitter and Instagram pages.

Tory leadership: Final 10 named as Michael Gove issues personal attack on Boris Johnson