Boris Johnson has insisted that the chances of Britain breaking away from the EU at the end of 2020 without a trade deal in place are “absolutely zero”.

Ahead of his first televised debate of the General Election campaign with Jeremy Corbyn, the Prime Minister expressed confidence that a re-elected Tory government would negotiate a free trade agreement within 11 months of Britain leaving the EU.

Under Conservative plans, Mr Johnson would re-introduce his Withdrawal Agreement in the Commons with a view to delivering Brexit by the current deadline of January 31.

That would mark the start of a transition period – set to run to the end of 2020 – in which the UK would continue to follow EU rules while negotiations on a trade deal take place.

However, many observers believe it is not enough time to get an agreement, opening up the prospect of Britain leaving without a deal unless Mr Johnson seeks an extension to the transition period – something he has vowed not to do.

But speaking during an election campaign visit to a boxing gym near Manchester, the Prime Minister was adamant there was no prospect of breaking with the EU at the end of 2020 without a trade agreement in place.

Asked in an interview with BBC local radio about the risk, he said: “I think they’re absolutely zero.”

He added: “People said I couldn’t get a deal with the EU in the three months that we had available and they said we couldn’t reopen the Withdrawal Agreement and that Brussels would never agree, and all this sort of stuff, and look what we did.

“We got a fantastic deal, it’s ready to go … it is supported by every single one of the 635 Conservative candidates standing at this election.”

At the same time, however, he reaffirmed his commitment that there would be no extension to the transition period.

General election 2019 poll of polls
(PA Graphics)

“It’s not going to be extended, there’s no reason to – we already have a zero-tariff, zero-quota arrangement with the EU – our regulations are already perfectly aligned,” he said.

“The reality is we’re there and we’re ready to go. All we need is a few weeks, we’ll bring this thing back in December if we’re lucky enough to be re-elected and we’ll put it back to Parliament and we’re out in January and we focus on the priorities of the British people.”

His intervention came as he prepared to go head-to-head with Mr Corbyn in an hour-long TV debate hosted by ITV.

The way was cleared for the encounter to go ahead after the High Court in London rejected a legal challenge by the Liberal Democrats and the SNP over the exclusion of their leaders.

With Labour trailing in the opinion polls, Mr Corbyn goes into the event – staged at studios in MediaCityUK, Salford – hoping for an opportunity to make up ground on the Conservatives.

General Election 2019
Boris Johnson will go head to head with Labour leader Jeremy Corbyn in the first TV debate of the campaign (Dominic Lipinski/PA)

In contrast, Mr Johnson, who was criticised for his reluctance to debate directly with his rivals in the Tory leadership election, will be seeking to avoid any misstep which hands ammunition to his opponents.

The debate takes place as:

– The Conservatives vowed to “come down hard” on knife crime with a pledge to immediately arrest and promptly charge anyone caught unlawfully with a blade.

– Shadow chancellor John McDonnell accused the Tories of handing tax breaks to billionaires, saying such levels of wealth were “obscene”.

– The Lib Dems pledged to put 1p on income tax to provide an additional £35 billion for the NHS.

– The Greens launched their election manifesto with a pledge to invest £100 billion a year in tackling climate change.

Ahead of their encounter, Mr Johnson sought to put pressure on Mr Corbyn with an open letter calling on him to say which way he would recommend people should vote in Labour’s proposed second EU referendum.

The Labour leader has come under fire over his refusal to say which way he would vote, even though other senior figures including Mr McDonnell and shadow foreign secretary Emily Thornberry have made clear they would back Remain.