Theresa May has been told to “face down” Jacob Rees-Mogg’s European Research Group (ERG) amid warnings more Conservative MPs could defect.

Three Tories have already left to join The Independent Group (TIG) and the Prime Minister has been warned that the influence of Brexiteers in the ERG could push others out of the party.

Former minister Phillip Lee, who has been the subject of speculation that he could also leave the Conservatives, said he was “staying to fight” – but said the ERG must be “dealt with”.

Heidi Allen, Anna Soubry and Sarah Wollaston quit the Conservatives this week, complaining about the influence of the ERG in Parliament and “Blukip” or “purple momentum” entryism in local associations.

Dr Lee met Mrs May in Number 10 on Thursday and told BBC Radio 4’s Today programme they had a “frank exchange of views”.

He expressed alarm at Brexit policy and “populist” decisions like Sajid Javid’s move to strip Shamima Begum of citizenship.

He said Mrs May “needs to face down the ERG properly” saying there were elements of the group that did not reflect the party he joined in 1992 and “it’s about time we dealt with them”.

Phillip Lee called on the Prime Minister to take on the European Research Group (Stefan Rousseau/PA)
Phillip Lee called on the Prime Minister to take on the European Research Group (Stefan Rousseau/PA)

Meanwhile Ms Allen suggested other “incredibly sympathetic” colleagues may soon be joining TIG.

She said the Conservative Party had “completely transformed itself” and there “won’t be a Tory party I recognise to go back to”.

She told ITV’s Good Morning Britain: “My suspicion is that if things continue as they are the ERG will continue and will be running things going forward.

“Colleagues who are incredibly sympathetic to Sarah, Anna and myself and what we’ve done, I suspect they will be coming across and be joining our group.”

Independent Group of MPs
(PA Graphics)

Ms Allen has suggested that ex-Labour MP Chuka Umunna is the obvious candidate to lead the group, but hinted that other potential leaders may be about to join.

“My view right now is that Chuka has brought us together,” she said.

“But like any leader in business, politics, it needs to be the best person to get the best out of that team.

“And given that we’re still going to have other colleagues come and join us I don’t think we can say who that leader’s going to be until we know the range of people that are going to be in our group.”

Mr Umunna told Good Morning Britain: “We’re not a political party at this stage.

“I think for all of us we were deeply, deeply unhappy in the parties that we were at. Just walking off the field would have been a cop out.

“We thought actually as Members of Parliament we’ve got mandate, we’re in a position to provide people with an alternative, whether that’s a party or a movement, we’re clear that we want to provide people with an alternative.”