This leaves just 68 days for the prime minister to secure a new deal, with neither side currently prepared to compromise on key issues.
The scenario leaves the UK facing a messy exit from the bloc, with food shortages and considerable border disruption expected, which could leave long-lasting economic scars on the country.
“The EU does tend to come to an agreement right at the end,” he said. “Clearly for us the walking away, as it were, would come on 31 October when we would take steps to come out … we would have by then made absolutely colossal extensive and fantastic preparations.”
Mr Johnson said he believed that other EU states, as well as the British public, now wanted to put Brexit behind them and move on.
“I think that it’s the job of everybody in parliament to get this thing done,” he said. “I think it’s what the people want, I also think by the way it’s what our friends and partners on the other side of the Channel want.
“They want this thing done, they want it over.
“You talk to our friends as I have done in the last few weeks and they are very enthusiastic about getting on with the future. They regard Brexit now as an encumbrance, an old argument. They want to talk about the new partnership that we’re going to build.”
The prime minister repeatedly refused to rule out suspending parliament in order to push through a no-deal Brexit.
Good morning and welcome to The Independent's live coverage of the G7 in Biarritz, as Boris Johnson holds a series of meetings ahead of the summit's end.
Boris Johnson has announced that Britain is to make an immediate donation of £10 million to help protect and restore the Amazon rainforest amid the wildfires devastating the region.
Here’s more from our political editor Andrew Woodcock.
Former PM Gordon Brown has called for parliament to order an independent inquiry into the consequences of a no-deal withdrawal from the EU.
Brown said MPs should seize control of the House of Commons agenda to ensure the full impact of leaving the EU without an agreement is made clear.
“I think what they should do is agree that they take over the business of the House of Commons for a day, as they did before, pass a law that says that the government must instruct and produce an independent report on the consequences of a no-deal,” he told BBC Radio 4’s Today programme.
“And that should be before the House of Commons before we ever go ahead. That would be a sensible way forward.”
Brown also branded the G7 “impotent” and said we were living in a “leaderless world”.
He explained: “When you have got an organisation that cannot agree on a communique, that has got no agreed agenda, that's got no agreement even on membership, and has broken down, as far as I can see, over the weekend into small huddles of individuals doing bilateral discussions – you’ve really got a leaderless world.
“It is rightly called by some the G Zero because the world seems to be more divided than I can remember.”
Australian prime minister Scott Morrison greeted Boris Johnson and immediately began talking about England’s cricket win as the pair met at the G7 summit in Biarritz.
“Congratulations on the Ashes,” he told Johnson.
Johnson replied that he was “not taking anything for granted” and Mr Morrison pointed out there were “two to go”.
The final two games of the series - which is currently level at one-all - will take place in September.
Labour’s shadow trade secretary Barry Gardiner said the “tragedy unfolding in the Amazon should not be used as a PR stunt” by Boris Johnson.
“The truth is that £10 million is an embarrassingly tiny contribution to deal with the situation in the Amazon which is part of the sustained anti-environment campaign being waged by a right-wing Brazilian government.
“Boris Johnson’s government has pointedly refused to ensure that UK companies are not aiding and abetting the destruction of the Amazon by ruling out from any trade deal beef raised on rainforest land burnt out by ranchers.”
Boris Johnson has called on the BBC to “cough up” the £745m annual cost of maintaining free TV licences for the over-75s.
Here’s all the details on No 10’s row with the Beeb over the decision to means-test the subsidy.
As few as six per cent of cross-border businesses in Ireland are prepared for cash-flow issues in the event of a no-deal Brexit, a report has found.
Here’s the latest on the warnings for traders.
Boris Johnson is using the closing stages of the G7 summit to hold a series of meetings with world leaders including Australian counterpart Scott Morrison.
The PM will also hold face-to-face meetings with Japanese leader Shinzo Abe, Egypt’s Abdel Fattah el-Sisi and outgoing Italian premier Giuseppe Conte.
Elsewhere in Biarritz, the leaders of the G7 nations will consider how to protect the environment, with Johnson pledging £10 million to help prevent the destruction of the Amazon.
Host Emmanuel Macron said there would not be a final communique today – an agreed statement backed by all the leaders.
The 2018 G7 summit ended in farce as Donald Trump withdrew his support for the text and Macron is keen to avoid a repeat performance.
Lib Dem leader Jo Swinson has written to Labour leader Jeremy Corbyn urging him to give up his hopes of leading a government of national unity if Boris Johnson is they manage to oust Boris Johnson through a vote of no confidence.
“Insisting you lead that emergency government will therefore jeopardise the chances of a no confidence vote gaining enough support to pass in the first place,” she said.
Our political editor Andrew Woodock has more.
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