A clean exit from the EU could be achieved by Boris Johnson becoming Prime Minister and forming an election agreement with the Brexit Party, its leader Nigel Farage has said.

The former UKIP chief said such a pact would require Mr Johnson to call a snap election.

“If Boris said ‘right, we’re ditching this terrible treaty, it’s the worst deal in history, I made a terrible mistake in voting for it, we’re ditching it’,” Mr Farage said at an event hosted by The Telegraph on Tuesday.

“‘We’re giving Europe notice – we’re leaving on the 31st of October on WTO (World Trade Organisation) terms. We’re going to do our utmost to make sure that in terms of terms of aviation, transport, the Port of Dover there is as little disruption as there possibly can be’ – then you might spring them into action and they might offer some sort of tariff-free deal.

“And if Boris did that, and he was prepared to go to House of Commons to be voted down, to lose a motion of confidence, to go the country on a general election on that ticket and with the support of people of like me – he would win a massive, thumping majority.”

He was then asked by the paper’s Christopher Hope to reiterate his support for a deal contingent on going to the polls.

“If he was prepared to do that of course I’d want to work with them, of course I’d do that,” he replied.

Mr Farage said on Sunday that there is “little chance” of the Conservatives delivering on the promise to leave the EU by October 31, even if the former foreign secretary becomes Prime Minister.

If Mr Johnson tries to force the issue through Parliament he will face “open civil war”, Mr Farage wrote in the Sunday Express.

His comments on Tuesday come amid concerns that his party could split the vote among Tory Brexiteers.

“To win the next general election we don’t have to become the Brexit Party, make an electoral pact with them in certain seats, or offer a coalition in Parliament,” Scottish Conservative leader Ruth Davidson said in a column for The Telegraph.

“We have to respect the referendum result and leave the EU, as we said we would,” she added.

“Doing a deal with the Brexit Party would be an admission of defeat. And we’re not dead yet.”