BORIS Johnson has made a "do or die" commitment to pull the UK out of the European Union by October 31 as he began a fightback against his opponent’s claim that he was a “coward” for shying away from the media spotlight.

Stirred by Jeremy Hunt’s criticism, the former Foreign Secretary has stepped back onto the campaign trail but again avoided questions about his private life.

He also refused to say if the picture of himself holding hands with his partner Carrie Symonds in a Sussex garden, which was splashed across many newspaper front pages today, was taken weeks ago. Suggestions have been made that the “loved up” photograph was planted on the internet to show the couple’s relationship was back on track in the wake of their much-publicised early morning row.

Mr Johnson used a series of broadcast interviews to set out his plans for Brexit, claiming the shock of the European election results would force both the Tories and Labour to acknowledge that the current impasse could not continue.

The frontrunner, who went on a walkabout in Surrey this afternoon, will find out whether he has achieved his ambition of becoming Tory leader when the results of the contest are announced on Tuesday July 23 under the timetable set out today by Conservative HQ.

He told TalkRadio the UK would be leaving the EU on the Halloween deadline "do or die, come what may".

Mr Johnson said some "positive energy" would help deliver Brexit, hitting out at the "pathetic" efforts of Theresa May's administration; a government in which he served as Foreign Secretary for two years until July 2018.

"I've never seen such morosity and gloom from a government," declared the London MP.

"For three years we've been sitting around wrapped in defeatism telling the British public that they can't do this or that. It is pathetic, it's absolutely pathetic."

But Mr Johnson could not escape continued questions about his private life after the events in the early hours of Friday morning when police were called to his partner’s flat in London’s Camberwell by neighbours.

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On LBC Radio, he was repeatedly challenged about whether his campaign was behind the release of a picture of himself with Ms Symonds in an attempt to show their relationship was going strong.

Asked where the photograph had come from, the former London Mayor replied: "The longer we spend on things extraneous to what I want to do...the bigger the waste of time."

In testy exchanges, he said there were "all sorts of pictures of me out on the internet which pop up from time to time".

When host Nick Ferrari suggested his hairstyle indicated it was an old picture, Mr Johnson said: "This conversation is now descending into farce."

Turning to Brexit, the contest’s frontrunner said "politics has totally changed" since March 29 and "we are staring down the barrel of defeat" which would focus minds in Parliament.

He went on: "People are looking at this thing and thinking 'Parliament is just not going to do this'. But, actually, they are."

The former Cabinet minister said that it was “vital as a country that we get ready to come out without an agreement if we must" but he argued it would be "bizarre" for the European Union to impose tariffs on trade in that event if the two sides were looking at a future deal.

He was forced to accept Britain could not have a “standstill” trade relationship with the EU after Brexit unless the other 27 EU member states agreed.

READ MORE: Watch: Boris Johnson repeatedly challenged in interview over Carrie Symonds picture 

“What you can’t do is unilaterally use a Gatt 24 solution,” Mr Johnson conceded, referring to the World Trade Organization rule. “But you could agree with our EU friends and partners to go forward together on that basis,” he insisted.

Mr Johnson's campaign was stepping up a gear following claims he was a "coward" from leadership rival Jeremy Hunt for shying away from debates, including a Sky News head-to-head originally scheduled for tonight.

Mr Hunt said he would answer questions on Twitter instead, saying Mr Johnson's refusal to take part was not fair on the public.

"Tonight I was meant to be debating Boris Johnson on Sky, answering questions about our plans for Britain. Sadly, Boris has pulled out, which I don't believe is fair on you, the public."

Mr Johnson had largely kept out of the public eye since the news broke about the row with Ms Symonds.

Police were called by worried neighbours after his partner was heard screaming and shouting "get off me".

On the BBC, Mr Johnson said: "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 ... in a way that is not fair on them."

Amber Rudd, the Work and Pensions Secretary, who is supporting Mr Hunt, called on Mr Johnson to spell out the details of his Brexit plan.

"This is an incredibly difficult situation and Boris needs to explain how he will deal with both sides of the Conservative Party that have concerns and try and break the impasse with the European Union," she told BBC Radio 4's Today, adding: "Enthusiasm and optimism is not sufficient."