Boris Johnson wanted to be the “romantic, patriotic” hero of Brexit despite believing the Leave campaign would be “crushed like a toad under the harrow”, David Cameron has said.

In an outspoken attack on his old colleague, the former prime minister suggested Mr Johnson had made a cynical decision to back Brexit in order to advance his own career.

Speaking to ITV News ahead of the publication of his long-awaited memoir, Mr Cameron said he was still haunted by the referendum result and he was “deeply sorry” for the chaos that has transpired.

Mr Cameron also condemned his successor’s decision to suspend parliament, and said it was a “disastrous” move to sack 21 senior Tory MPs for rebelling against the government.

Despite being an outspoken Brexiteer, Mr Johnson famously wrote two newspaper columns arguing for and against Brexit, as he wrestled with the decision over which side to support.

“I spoke to him at length about it and I said, ‘Boris you’ve never been in favour of leaving the EU, so why now there’s a better deal on offer, are you in favour of leaving now?’” Mr Cameron said.

Asked about his successor’s motives, Mr Cameron said: “My conclusion is: he thought that the Brexit vote would be lost but he didn’t want to give up the chance of being on the romantic, patriotic nationalistic side of Brexit.

“Minutes before he went out to explain why he was going to be on the side of Brexit, he sent me a text saying, ‘Brexit will be crushed like a toad under the harrow.’ But I can only conclude that – he’d never argued for it before – he thought it was going to lose and that’s why he made the choice.”

Pressed on whether it was a cynical decision, rather than a genuine view, Mr Cameron said: “He’d never argued for it before and so why argue for it when there’s a better deal on offer?

“And as I put to him, ‘There will be another treaty; another renegotiation. You might well be the prime minister at the time when that comes about and you can get an even better deal for Britain.’”

The latest comments come after the ex-Tory leader revealed that Mr Johnson asked if Michael Gove was “a bit cracked” when he famously betrayed Mr Johnson and announced his own leadership bid.

The shock move forced Mr Johnson to withdraw from the contest, which was later won by Theresa May.

In his first major TV interview, Mr Cameron was visibly emotional when asked if the decision to call the referendum haunted him.

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The former prime minister appeared close to tears, saying: “Yeah, of course. You know, this is a huge decision for our country and I think we’ve taken the wrong path. As I’ve said, it can be made to work.

“If you’re asking me, do I have regrets? Yes. Am I sorry about the state the country’s got into? Yes.

“Do I feel I have some responsibility for that? Yes. It was my referendum, my campaign, my decision to try to renegotiate.

“And I accept all of those things and people, including those watching this programme, will have to decide how much blame to put on me.”

Asked if he would apologise, Mr Cameron said: “I’m deeply sorry about all that’s happened.

“There isn’t a day that goes by when I don’t think about all the decisions I made and all that has followed.

Thousands protest after Boris Johnson requests to suspend parliament Show all 29 1 /29 Thousands protest after Boris Johnson requests to suspend parliament Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament An anti-Brexit supporter raises a sign during a protest in front of the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered on Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Vudi Xhymshiti) Vudi Xhymshiti AP Thousands protest after Boris Johnson requests to suspend parliament Downing Street Anti-Brexit demonstrators hold placards as they protest outside of Downing Street in London on August 28, 2019. - British Prime Minister Boris Johnson sparked fury Wednesday among pro-Europeans and MPs opposed to a no-deal Brexit by forcing the suspension of parliament weeks before Britain's EU departure date. The pound slid on the surprise news, which opponents branded a "coup" and a "declaration of war" but Johnson claimed was necessary to allow him to pursue a "bold and ambitious" new domestic legislative agenda. (Photo by DANIEL SORABJI / AFP)DANIEL SORABJI/AFP/Getty Images DANIEL SORABJI AFP/Getty Images Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament Anti-Brexit supporters take part in a protest in front of the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered on Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Vudi Xhymshiti) Vudi Xhymshiti AP Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament to Downing Street TOPSHOT - Anti-Brexit demonstrators hold placards as they take part in a protest march from Britain's Houses of Parliament to Downing Street in London on August 28, 2019. - British Prime Minister Boris Johnson announced Wednesday that the suspension of parliament would be extended until October 14 -- just two weeks before the UK is set to leave the EU -- enraging anti-Brexit MPs. MPs will return to London later than in recent years, giving pro-EU lawmakers less time than expected to thwart Johnson's Brexit plans before Britain is due to leave the European Union on October 31. (Photo by DANIEL SORABJI / AFP)DANIEL SORABJI/AFP/Getty Images DANIEL SORABJI AFP/Getty Images Thousands protest after Boris Johnson requests to suspend parliament Downing Street Anti-Brexit supporters gather outside the Prime Minister's residence 10 Downing Street in London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament LONDON, ENGLAND - AUGUST 28: Pro-EU supporters protest outside the Houses of Parliament on August 28, 2019 in London, England. British Prime Minister Boris Johnson has written to Cabinet colleagues telling them that his government has requested the Queen suspend parliament for longer than the usual conference season. Parliament will return for a new session with a Queen's Speech on 14 October 2019. Some Remain supporting MPs believe this move to be a ploy to hinder legislation preventing a No Deal Brexit. (Photo by Peter Summers/Getty Images) Peter Summers Getty Images Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament epa07799808 A protestor outside the Houses of Parliament in Westminster, London, Britain, 28 August 2019. The UK government is to suspend Parliament after the summer break, a move that might block MPs from voting against a possible no-deal Brexit.. EPA/WILL OLIVER WILL OLIVER EPA Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament Anti-Brexit supporters take part in a protest near the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Whitehall TOPSHOT - Demonstrators hold placards as they protest on Whitehall, near the entrance to Downing Street in London on August 28, 2019. - British Prime Minister Boris Johnson sparked fury Wednesday among pro-Europeans and MPs opposed to a no-deal Brexit by forcing the suspension of parliament weeks before Britain's EU departure date. The pound slid on the surprise news, which opponents branded a "coup" and a "declaration of war" but Johnson claimed was necessary to allow him to pursue a "bold and ambitious" new domestic legislative agenda. (Photo by DANIEL SORABJI / AFP)DANIEL SORABJI/AFP/Getty Images DANIEL SORABJI AFP/Getty Images Thousands protest after Boris Johnson requests to suspend parliament Houses of Parliament Anti-Brexit supporters take part in a protest at College Green near the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters take part in a protest at College Green near the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Protestors from the European Movement in Scotland hold a walking vigil on the Royal Mile, Edinburgh, to demonstrate against Prime Minister Boris Johnson temporarily closing down the Commons from the second week of September until October 14 when there will be a Queen's Speech to open a new session of Parliament. PRESS ASSOCIATION Photo. Picture date: Wednesday August 28, 2019. See PA story POLITICS Brexit. Photo credit should read: Jane Barlow/PA Wire Jane Barlow PA Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters shout slogans as they gather outside the Prime Minister's residence 10 Downing Street in London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters take part in a protest at College Green near the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters take part in a protest at College Green near the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters gather outside the Prime Minister's residence 10 Downing Street in London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters take part in a protest at College Green near the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Shadow home secretary Diane Abbott addresses protesters outside the Houses of Parliament, London, to demonstrate against Prime Minister Boris Johnson temporarily closing down the Commons from the second week of September until October 14 when there will be a Queen's Speech to open a new session of Parliament. PRESS ASSOCIATION Photo. Picture date: Wednesday August 28, 2019. See PA story POLITICS Brexit. Photo credit should read: Kirsty O'Connor/PA Wire Kirsty O'Connor PA Thousands protest after Boris Johnson requests to suspend parliament epa07799846 Protesters gather outside the Houses of Parliament in Westminster, London, Britain, 28 August 2019. The UK government is to suspend Parliament after the summer break, a move that might block MPs from voting against a possible no-deal Brexit. EPA/WILL OLIVER WILL OLIVER EPA Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters gather outside the Prime Minister's residence 10 Downing Street in London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters carry a flare near the Cenotaph in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit. (AP Photo/Matt Dunham) Matt Dunham AP Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit demonstrators hold placards as they protest outside of Downing Street in London on August 28, 2019. - British Prime Minister Boris Johnson sparked fury Wednesday among pro-Europeans and MPs opposed to a no-deal Brexit by forcing the suspension of parliament weeks before Britain's EU departure date. The pound slid on the surprise news, which opponents branded a "coup" and a "declaration of war" but Johnson claimed was necessary to allow him to pursue a "bold and ambitious" new domestic legislative agenda. (Photo by DANIEL SORABJI / AFP)DANIEL SORABJI/AFP/Getty Images DANIEL SORABJI AFP/Getty Images Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit demonstrators hold placards as they protest outside of Downing Street in London on August 28, 2019. - British Prime Minister Boris Johnson sparked fury Wednesday among pro-Europeans and MPs opposed to a no-deal Brexit by forcing the suspension of parliament weeks before Britain's EU departure date. The pound slid on the surprise news, which opponents branded a "coup" and a "declaration of war" but Johnson claimed was necessary to allow him to pursue a "bold and ambitious" new domestic legislative agenda. (Photo by DANIEL SORABJI / AFP)DANIEL SORABJI/AFP/Getty Images DANIEL SORABJI AFP/Getty Images Thousands protest after Boris Johnson requests to suspend parliament LONDON, ENGLAND - AUGUST 28: Pro-EU supporters protest outside the Houses of Parliament on August 28, 2019 in London, England. British Prime Minister Boris Johnson has written to Cabinet colleagues telling them that his government has requested the Queen suspend parliament for longer than the usual conference season. Parliament will return for a new session with a Queen's Speech on 14 October 2019. Some Remain supporting MPs believe this move to be a ploy to hinder legislation preventing a No Deal Brexit. (Photo by Peter Summers/Getty Images)(Photo by Peter Summers/Getty Images) Peter Summers Getty Images Thousands protest after Boris Johnson requests to suspend parliament Anti-Brexit supporters continue to participate in a late evening protest in front of the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered on Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Vudi Xhymshiti) Vudi Xhymshiti AP Thousands protest after Boris Johnson requests to suspend parliament London metropolitan police talk with anti-Brexit supporters in front of the Houses of Parliament in central London, Wednesday, Aug. 28, 2019. British Prime Minister Boris Johnson maneuvered on Wednesday to give his political opponents even less time to block a no-deal Brexit before the Oct. 31 withdrawal deadline, winning Queen Elizabeth II's approval to suspend Parliament. (AP Photo/Vudi Xhymshiti) Vudi Xhymshiti AP Thousands protest after Boris Johnson requests to suspend parliament LONDON, ENGLAND - AUGUST 28: A Pro-EU supporter raises her fist during a protest outside the Houses of Parliament on August 28, 2019 in London, England. British Prime Minister Boris Johnson has written to Cabinet colleagues telling them that his government has requested the Queen suspend parliament for longer than the usual conference season. Parliament will return for a new session with a Queen's Speech on 14 October 2019. Some Remain supporting MPs believe this move to be a ploy to hinder legislation preventing a No Deal Brexit. (Photo by Peter Summers/Getty Images) Peter Summers Getty Images Thousands protest after Boris Johnson requests to suspend parliament LONDON, ENGLAND - AUGUST 28: Pro-EU supporters protest outside the Houses of Parliament on August 28, 2019 in London, England. British Prime Minister Boris Johnson has written to Cabinet colleagues telling them that his government has requested the Queen suspend parliament for longer than the usual conference season. Parliament will return for a new session with a Queen's Speech on 14 October 2019. Some Remain supporting MPs believe this move to be a ploy to hinder legislation preventing a No Deal Brexit. (Photo by Peter Summers/Getty Images)(Photo by Peter Summers/Getty Images) Peter Summers Getty Images Thousands protest after Boris Johnson requests to suspend parliament LONDON, ENGLAND - AUGUST 28: Pro-EU supporters protest outside the Houses of Parliament on August 28, 2019 in London, England. British Prime Minister Boris Johnson has written to Cabinet colleagues telling them that his government has requested the Queen suspend parliament for longer than the usual conference season. Parliament will return for a new session with a Queen's Speech on 14 October 2019. Some Remain supporting MPs believe this move to be a ploy to hinder legislation preventing a No Deal Brexit. (Photo by Peter Summers/Getty Images)(Photo by Peter Summers/Getty Images) Peter Summers Getty Images

“But when I go back to that decision, that Britain’s position needed to be sorted and we needed a renegotiation and a referendum, I believed then that was the right approach.”

Asked if he had any regrets, Mr Cameron said: “I have huge regrets. I regret that we lost the campaign. I regret I let expectations about the negotiation run far too high.

“I regret some of the individual decisions we made in the campaign. I think perhaps there’s a case to say the timing could have been different.”

In extracts – published over the weekend – from For the Record, Mr Cameron described Mr Gove as a “foam-flecked Faragist”.