The politician-turned editor of the Evening Standard, who has been a vocal critic of Theresa May - who sacked him from the Cabinet in 2016 - also attacked the Prime Minister’s handling of negotiations.
He accused her of following a “Brexit means Brexit” ideology because she backed Remain at the 2016 referendum, “albeit sotto voce”, and therefore “had to prove her Brexit credentials”.
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He added: “That was essentially a massive mistake by the Conservative administration, which it was punished for at the general election because the Conservative Party decided to embrace the Brexit result in such a way as to essentially dismiss the views of those who voted Remain, treat them as saboteurs or traitors, and run against urban Britain.”
Mr Osborne, who said he had warned then PM David Cameron against holding the referendum in the first place, also attacked the “reckless decision of hard Brexiteers” to pursue a no-deal Brexit, saying: “I don’t think the country voted to mobilise the Army, stockpile medicine, hoard food and go around the world buying every fridge available.
“That is not what was offered and that is now what is happening.”
Theresa May’s Withdrawal Agreement is due to be voted on by MPs in January. But few expect it to be approved by a heavily divided Commons, and Tory MPs including Cabinet ministers appear to have begun to polarise between those who might support a no-deal Brexit and those who would actively battle against it.
Justice Minister David Gauke said on Friday he would find it “very difficult” to remain in Theresa May’s Government if the UK appeared on course to crash out of the European Union without a deal, while several pro-EU backbenchers have threatened to quit the party.
Mr Osborne, who resigned as MP for Tatton after being ousted by Mrs May, told Today that if he had remained in politics he would now be having to go along “with a whole load of things which I profoundly disagree with”, citing no-deal preparations like readying troops.
He said: “Of course I think ‘perhaps I should have stayed’ and I could have been part of this melee in the Conservative Party at the moment.
“I would have essentially tried to steer a) the country away from the rocks to which it is heading at the moment, and b) the Conservative Party away from a prolonged period of opposition, which is where I think it is heading unless it engages more with modern Britain.”
He praised MPs attempting to stymie a no-deal Brexit, saying “the British political system is trying to pull the country back from this cliff edge of the referendum result”.
He added: “My view is a general election is at the moment an under-reported likelihood for 2019 because in the British system the simplest way to solve political impasses has been to return to the public and a general election.”
However he suggested Tory MPs could avoid that extreme measure by supporting a second referendum.
Mr Osborne’s interview came after Labour leader Jeremy Corbyn said his party would continue with Brexit if it won a snap general election in the new year.
The opposition leader told the Guardian he would “go back and negotiate and see what the timetable would be” with Brussels if Mrs May triggered a vote and lost, thrusting his party into power.
Mr Corbyn told the paper he would advocate Brexit if there was a second referendum on the issue, saying: “It would be a matter for the party to decide what the policy would be; but my proposal at this moment is that we go forward, trying to get a customs union with the EU in which we would be able to be proper trading partners.”
Mr Corbyn also attacked Brussels over its rules on state aid and competition.
He told the Guardian: “I think the state aid rules do need to be looked at again because quite clearly, if you want to regenerate an economy, as we would want to do in government, then I don’t want to be told by somebody else that we can’t use state aid in order to be able to develop industry in this country.”