Nigel Farage warns Brexiteers Boris Johnson will break his promises on Brexit

The Brexit Party leader said there appears to be “little chance” of the Tories delivering on Johnson’s pledge to take Britain out of the EU on October 31.

Criticising an absence of “post-Brexit vision” from Conservative leadership candidates, among whom the former foreign secretary is the clear front-runner, he highlighted that they had all voted for May’s doomed deal when it last went before the Commons.

Writing in the Sunday Express, Farage said: “Even if Boris Johnson becomes party leader and prime minister, the best we are likely to get from these Tories is a rehash of Mrs May’s appalling Withdrawal Agreement; a warmed-over version of her worst deal in history.”

The withdrawal agreement was rejected by MPs three times before she resigned as Tory party leader in May, triggering the leadership contest.

Launching his campaign, Johnson said MPs they will “reap the whirlwind” if they try to thwart Brexit again.

But Farage warned voters would see another delay to Brexit as a “another betrayal of explicit promises made by a Tory prime minister”.

Nonetheless, if Johnson tries to force the issue through parliament he will face “open civil war”, Mr Farage said.

He added: “I have no doubt that if (Johnson) wins, then initially there will be something of a ‘Boris bounce’ in Tory support.

“But, given the dire state of Conservative fortunes, they will need a bounce about as high as Big Ben.

“The Conservative Party’s problems are too profound to be solved by a change of face at the top. Any Boris bounce is likely to be short-lived.”