The Brexit party’s leader, Nigel Farage, has been heavily criticised by Boris Johnson’s team as “not fit and proper” in an outright rejection of his offer of a pre-election, no-deal Brexit pact.
Farage offered to help the embattled prime minister secure a majority at a snap general election, on the proviso he dropped plans to renegotiate the Brexit withdrawal agreement and the backstop arrangement on the Northern Irish border.
He said the prime minister should accept he needed the Brexit party’s help to take out key Labour seats but vowed to be his “deadliest enemy” if he renegotiated with Brussels and abandoned what he called a “clean” no-deal departure from the EU.
A bitter war of words quickly escalated between the two camps, with No 10 curtly rebuffing his proposal.
A spokesperson said: “The PM will not be doing a deal with Nigel Farage.”
A senior Tory source added: “Neither Nigel Farage nor Arron Banks are fit and proper persons and they should never be allowed anywhere near government.”
Banks co-founded the Leave.Eu campaign group and is a long-standing political ally of Farage, but Farage has said he is not a donor to the Brexit party.
Farage is asking the Tories to stand aside in 90 constituencies in a “non-aggression pact” to avoid splitting the vote in leave seats. He believes the Brexit party could win 40 seats and will be targeting south Wales, the Midlands and the north-east of England should there be an election.
He believes the pact could land the Tories with a majority of between 60 and 100 MPs.
It is being offered on the condition Johnson abandons any attempt to strike a deal with the EU and instead goes ahead with a no-deal Brexit.
Farage said: “If they go down the withdrawal agreement route, we will be their deadliest enemies. We can be their best friends, or their worst enemies.
“I very much hope that at some point Boris Johnson will simply look at the numbers and say [working together] is unavoidable. We have to do something here. It’s the only way we can win. If we stand against them they cannot win a majority. We end up with another hung parliament.”
Farage will stand as a candidate, making it his eighth attempt to become an MP. He said he would not go near the 28 seats of those Tories in the European Research Group who voted against Theresa May’s withdrawal agreement three times.
The prime minister’s chief strategist, Dominic Cummings, who ran the Vote Leave campaign, has been a vocal critic of Farage in the past. Farage said he accepted there was “personal animosity” towards him.
The Brexit party believes the perfect conditions under which they could take seats would be in a leave-voting constituency with a current remainer Labour MP, without a Conservative on the ballot paper. Farage also said voters were more likely to back them in constituencies in which his former party, Ukip, had previously come second.
Bolsover, Mansfield, Bassetlaw and South Yorkshire Coalfield seats are among their targets.
Farage said: “If Boris Johnson really thinks he can win in those seats I don’t know what he’s smoking ... it just isn’t going to happen.”
He said traditionally Labour-voting constituencies could be persuaded by a hard Brexit manifesto.
The new app Pericles, inspired by technology used by Donald Trump, has been launched by the Brexit party, which enables activists to access the electoral register.
Richard Tice, the Brexit party’s chairman and an MEP, said: “You can go into a constituency, click on a street, go in and you know who is on the electoral roll there and see it on a map and that way we can register their interest, a yes, no or maybe. That will help us also on the actual election day in terms of getting out the vote.
“This is a new piece of technology, no one else in the political system in the UK has this and this is what we’ve been doing over the summer.”
The party is polling on around 14-15%.
Farage said: “Given that we think the Conservatives will take a real kicking on 1 November onwards, [and] a general election is unavoidable at some point, it seems to us there’s a very obvious deal to be done.
“And the opportunity here for Boris Johnson is massive because in some of those key marginal seats he absolutely has to win.”
