No transition period without EU agreement, Boris Johnson admits

Boris Johnson broke cover on Monday night in an interview for the BBC in which he was forced to admit there would be no transition period without the EU’s agreement in the event of a no-deal Brexit.

In the interview with the corporation’s political editor, Laura Kuenssberg, his first of the Conservative leadership campaign, Johnson also vowed he would never disclose what led to the loud row with his partner Carrie Symonds, which led neighbours to call police.

Johnson repeatedly swerved questions on the detail of his Brexit plan but suggested he was not prepared to rip up the entire agreement, as hard Brexiter supporters have insisted he has promised to do.

He said he intended to “make progress with the bits of the withdrawal agreement that we have” but there could be “creative ambiguity” about the payment of £39bn to the EU agreed as part of the deal.

He said those issues, including the Irish border, would be tackled “on the other side of 31 October during what’s called the implementation period.”

Johnson then admitted the UK would not be entitled to an implementation period without signing up to the current withdrawal agreement. “That’s certainly what I’m aiming for … to get an implementation period,” he said.

He said he believed there were “abundant, abundant technical fixes that can be introduced to make sure that you don’t have to have checks at the border” but conceded there was “no single magic bullet” to solve the issue of the Irish border.

However, he said there was now “a real positive energy about getting it done … I think on both sides of the channel there’s an understanding that we have to come out, but clearly parliament has voted three times against the backstop arrangements.”

Related: Boris Johnson plans media blitz after criticism he's dodged public scrutiny

Johnson said he believed there would be a “very different outcome” with UK negotiators determined to find an alternative to the backstop. “We were committed to it. We actually helped to invent it. We were the authors of our own incarceration. Take that away. Change the approach of the UK negotiators and you have a very different outcome,” he said.

He said he would make an absolute guarantee the UK would leave – deal or no deal – by 31 October. “It is not where I believe for a moment we will end up. But in order to get the result that we want … The common sensical thing to do is to prepare for a WTO exit.”

Johnson said he believed he could get a no-deal Brexit through parliament if necessary, despite Tory MPs warning a prime minister headed for no deal would be likely to be brought down by Conservative rebels in a confidence vote.

Related: I was Boris Johnson’s boss: he is utterly unfit to be prime minister | Max Hastings

“I think that MPs on both sides of the House also understand that they will face mortal retribution from the electorate unless we get on and do it,” he said.

Separately, Johnson said that he would never go into what had occurred between him and Symonds on the night the police were called to her flat.

“I do not talk about stuff involving my family, my loved ones. And there’s a very good reason for that. That is that, if you do, you drag them into things that, really is, is, in a way that is not fair on them,” he said.