Nigel Farage has said that if Boris Johnson backs a trade deal with the EU based on the withdrawal agreement which fails to deliver a full Brexit, then his Brexit Party “will be prepared to re-start the fight”.

Brexit negotiations are at a tense standoff, with Prime Minister Johnson announcing last week the UK should prepare for a no-deal, clean-break Brexit at the end of the transition period on January 1st, 2021, because Brussels remains intransigent on key issues of Britain regaining full sovereignty. The prime minister also rebuffed EU offers to send Michel Barnier to London for negotiations this week, unless the bloc changes its negotiation strategy.

Hitherto, Brussels has demanded that all movement come from the UK, notably on continued fishing rights for EU fishermen and the UK’s adherence to anti-competition rules. Barnier, however, suggested accommodation from the EU’s side, telling the European Parliament on Wednesday that a deal may be in place by the deadline “if both sides are willing to compromise”.

Sources in Brussels and London told The Telegraph on Tuesday that Mr Barnier could be in London as soon as Thursday to recommence negotiations, in what the newspaper suggested would be a precursor to a free trade agreement being signed.

Writing in The Telegraph on Wednesday, Mr Farage said that despite the tough talk on both sides, he believes that a deal will be signed, with the French making concessions on fishing and the UK surrendering on state aid rules.

However, Mr Farage warned that such a deal — forming a new EU treaty, which Brussels “Revere[] like the Bible” — that is based on the Withdrawal Agreement “will come back to haunt them over the next four years” and urged the prime minister instead to go for a no-deal, where the UK trades with the bloc on World Trade Organization (WTO) terms.

“If Johnson went down this path, I would support him 100 per cent and by the time of the next general election, there would be a real possibility of a Canada-style free trade agreement,” the Brexiteer wrote.

He said: “If the government does decide to take the easy way out by opting to do a deal based on the Withdrawal Agreement, I know that many of my excellent colleagues in the Brexit Party will be prepared to re-start the fight. As Ukip proved during David Cameron’s time in Downing Street, highly motivated insurgent political parties can split the Conservatives very effectively. I genuinely hope it does not come to this, but Johnson should be under no illusions about how serious this situation is.”

Recent YouGov polling would appear to back the Brexit Party leader’s remarks. Mr Farage observed that despite party activity having been “pretty negligible”, the Brexit Party had gained two percentage points — going from three per cent to five per cent — in just one week, trailing the Liberal Democrats by only one per cent.

Eight per cent of those BP supporters had voted Tory at the last election, with Mr Farage saying those people had likely “lent” their votes to the Conservative Party on the promise that Boris Johnson would deliver a real Brexit.

Adding: “I am certain that this steady trickle of those unhappy with the ongoing Brexit negotiations will become a flood if the government is seen to give in to the EU’s representative, Michel Barnier.”