Brexit Party leader Nigel Farage has issued a withering attack on the three MEPs who quit the party and are now urging voters to back the Conservatives in the election.

He told the BBC that Annunziata Rees-Mogg, Lance Forman and Lucy Harris had strong personal links to the Tories and this comes as a fourth MEP, John Longworth former Leave Means Leave chair, lost the whip on Wednesday for criticising the party’s election strategy.

The Brexit Party, which is not contesting seats won by the Conservatives in the 2017 general election, has maintained it is taking votes away from Labour in Leave-supporting areas where it is standing and in fact would help the Brexit cause. These MEP’s argue that all Brexit Party candidates shoudl stand down as it would save the Tories from losses to the pro-EU Liberal Democrats in the south of England.

Asked about the resignations of Ms Rees-Mogg, Ms Harris and Mr Forman from his party, Mr Farage told the BBC’s Andrew Neil: “One of them is the sister of a cabinet minister. Another one has a boyfriend working for that cabinet minister and another one is a personal friend of Boris Johnson’s.”

When challenged by Andrew Neil on whether he was smearing the MEPs, Mr Farage said he was presenting the facts.

“They joined the Brexit Party. They joined the coalition that I put together. They clearly were disaffected with Mrs [Theresa] May as leader,” he said. “We are not the Conservative Party. I tell you something – Boris Johnson’s deal unamended is unacceptable. I certainly stand by that.”

Ms Rees-Mogg, a former Tory parliamentary candidate and sister of Commons Leader Jacob Rees-Mogg, said it was tragic that the Brexit Party are now the very party risking Brexit.

“It is clear to me that the Brexit Party is splitting the vote of Leavers in marginal and not-so-marginal constituencies.

The Brexit Party are permitting votes to go away from the Conservatives, providing us with a Remain coalition that will do anything not to honour the Brexit referendum.”

Ms Rees-Mogg said it had “not been an easy decision for any of us” to quit the Brexit Party, but “we all feel it’s one we had no choice but to make”.

She said that Mr Johnson’s Brexit deal was “the only Leave option we have”, with the others being “more damaging delays, a second Remain-Remain referendum or straight revoke”.

She was also irked by suggestions that her brother had influenced her decision as disturbingly old-fashioned: “We have completely independent views from each other and I am only concerned about Brexit.”

The four MEPs have said they will continue to receive their full EU salaries and perks despite being elected on a Brexit Party ticket with Lucy Harris saying they would stay as MEPs in order to vote for the prime minister’s withdrawal agreement.