The Cumbrian MP battling to become the country's next Prime Minister has become the politician most likely to topple Boris Johnson, according to bookmaker William Hill.

After beginning as a rank outsider, Penrith and the Border MP Rory Stewart has seen his popularity rocket.

According to William Hill, the odds for succeed Theresa May as Prime Minister are now 10/1.

That puts him ahead of all the other candidates who are challenging Johnson, including Foreign Secretary Jeremy (14/1) and Environment Secretary Michael Gove (20/1).

The odds were released today after Stewart turned in a confident performance at last night's Channel 4 would-be leaders debate, which heard from all the candidates except Boris Johnson.

After accusing his rivals of pursuing a "competition in machismo", Stewart told viewers: "I have spent the last few week travelling around this country, from Londonderry to Derby, and everywhere that I have been I have felt a sense of palpable anger of a country that feels less than the sum of its parts. I began as the rank outsider in this race.

"100/1 against me.

"According to my wife today, I am now number 2 at the bookies.

"But I am still an outsider and I am campaigning on telling the truth as I see it and never making promises that we can't deliver. I would invite you to send me through to that final round round so that we can make this great party and this great country, again, something founded on honest and trust."

Away from the world of betting, there was a positive response to Stewart's TV performance last night.

Daily Telegraph columnist Michael Deacon heaped praise on the Cumbria MP.

In his column today, he wrote: "If you were to judge it by the response of the studio audience, Channel 4’s debate had only one winner. Rory Stewart got more rounds of applause than any other candidate – and, at the end, when each took turns to sum up, he was the only candidate to get a round of applause at all.

"The audience, apparently, was made up of floating voters who’d declared themselves open to voting Tory. And, it seemed, they liked what they saw.

Why? I think, at least in part, it was the way Mr Stewart set himself apart from the other four (Michael Gove, Jeremy Hunt, Sajid Javid and Dominic Raab). Mr Stewart is, as he said himself, the outsider, and he was happy to behave like one."

In a tweet, the Bournemouth East MP Tobias Ellwood said: "First hustings completed. As the odds show - the public’s view is cementing. @BorisJohnson vs @RoryStewartUK would produce a truly riveting contest that would help improve our brand & would be followed not just by the Party faithful but a country we must urgently re-engage with."

Carlisle City Council Leader John Mallinson, who leads the Conservatives at the authority, said: "I think Rory did extremely well, as I expected he would.

"With him being a local MP, I know him very well and he was really good.

"The other one to watch, I thought, was Sajid Javid.

"Personally, I think Rory is the one to watch. It's entirely possible that he could be the one in No 10 [Downing Street]. Rory is the one to give Boris a run for his money."

Mr Mallinson added that he and Stewart occupy the same wing of the Conservative Party - the moderate middle-ground.