TORY leadership contender Rory Stewart has said he could not serve in a government led by Boris Johnson pushing a no-deal Brexit agenda.

The International Development Secretary is a member of the centre-right of One Nation group Conservative MPs who are opposing the election of a hard Brexiteer such as the former Foreign Secretary.

“I could not serve in a government whose policy was to push this country into a no-deal Brexit. I could not serve with Boris Johnson,” Stewart said in a BBC radio interview yesterday.

“I spoke to Boris, I suppose, about two weeks ago about this and I thought at the time he had assured me that he wouldn’t push for a no-deal Brexit.

“So, we had a conversation about 20, 25 minutes and I left the room reassured by him that he wouldn’t do this.

“But, it now seems that he is coming out for a no-deal Brexit.”

Stewart, 46, a former Prisons Minister, who grew up in Scotland, added there was no majority in the Commons for no deal, stating: “I think it would be a huge mistake. Damaging, unnecessary, and I think also dishonest.”

Johnson is the clear favourite of Tory members to succeed Theresa May as party leader and Prime Minister with 39% backing him, according to an opinion poll published earlier this month. The YouGov poll found he was also the favourite candidate of Tory members in Scotland, though less so than in the UK overall with 28% putting him as their first choice. Stewart was the first choice of 4% of UK Tory members and 10% of members in Scotland.

Johnson told a conference in Interlaken, Switzerland on Friday: “We will leave the EU on 31 October, deal or no deal.”

The Tory leadership battle will officially start on 10 June, three days after May stands down with the winner in post by the end of July.

There are already almost 20 possible contenders, with Matt Hancock, 40, the fifth confirmed candidate to throw his hat into the ring yesterday.

He said he would take a different approach to try and get Commons support for a Brexit deal saying May “didn’t start by levelling with people about the trade-offs” between access to the European single market and sovereignty.

Hancock opposed an early election as a way out of the Brexit impasse.

“Some of my contenders may say that if they don’t get their preferred option, whether it be no deal or something else, then they’ll have a general election.

“I put it to you that would be a disaster for the country and it would risk Corbyn by Christmas,” he added.

Under the rules for the party’s leadership contest Tory MPs whittle all the candidates down in a series of voting rounds to two contenders whose names then go forward to a final ballot of all 124,000 party members.

The developments come as Labour insisted it would force a Commons vote of no confidence in the new Prime Minister as soon as possible.

Asked if his party would force a no confidence vote by MPs in May’s successor when he or she takes office, Shadow Chancellor John McDonnell told the BBC Radio Four Today programme: “Yes. Because we believe any incoming Prime Minister in these circumstance should go to the country anyway and seek a mandate.”