Remain-backing parties will forge a deal in more than 70 seats at a general election in a move that could leave them as kingmakers in the House of Commons, an MP has claimed.

Heidi Allen, a former Conservative MP who joined the Lib Dems on Monday, told Sky News her "Unite to Remain" strategy could have a major impact on the make-up of parliament when voters next go to the polls.

Under her plan, the Lib Dems, Green Party and Plaid Cymru will agree on a single candidate in some constituencies, while they will also not compete in seats where there is an incumbent Remain-backing independent MP.

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Ms Allen, who confirmed she will stand for the Lib Dems in her current South Cambridgeshire seat at the next election, told Sky News: "We're looking at the whole of England and Wales - the dynamics are slightly different in Northern Ireland and Scotland, as you would imagine.


"But I'm hopeful it will be over 70 seats."

Ms Allen was elected as a Tory MP in 2015 but quit the party in February this year to join what was to become Change UK, of which she was interim leader.

Following a row about whether the nascent party should support the Lib Dems in some regions in May's EU elections, Ms Allen left to sit as an independent MP.

She hinted she could have joined the Lib Dems sooner, but had wanted to secure her "Unite to Remain" plan first.

"That was important for me to broker that as an independent - to make sure I was balanced and fair and get the parties trusting each other and working together," she added.

"That's making good progress now, I'm really hopeful we'll have a good deal.

"So it's time now for me to look at the best way to represent my constituents - who are very heavily Remain in South Cambridgeshire - and that's why I've joined the Lib Dems, but people have been expecting me to do it for a while."

Brexit and the border simplified

Ms Allen predicted the next election would again result in no party winning a majority, which might see the Remain-backing alliance holding the balance of power.

"I think we would find ourselves most likely in a hung parliament again," Ms Allen added.

"That's why we've been preparing for this Unite to Remain initiative and why I've stayed independent for as long as I have - because it is so important.

"It would mean, if as successful as I believe it could be, we could hold the balance of power keeping both a Jeremy Corbyn-majority government and a Boris Johnson or Nigel Farage, let's be fair - the Brexit Party have candidates too - we would keep both ideological fringes out of majority power.

"And then the dynamics in the House of Commons could shift tremendously."

Ms Allen is the fourth former Tory MP - joining Sarah Wollaston, Phillip Lee and Sam Gyimah - to join the Liberal Democrats in recent months.

Ex-Labour MPs Chuka Umunna, Luciana Berger and Angela Smith are also among the Lib Dems' now 19 MPs.