A founding member of the Independent Group of MPs has offered to keep Theresa May in power if she agrees to hold a second referendum on Brexit.

Former Labour MP Gavin Shuker set out the deal, saying it would be "in the national interest”.

But he said it depended on the Prime Minister agreeing to hold "a confirmatory referendum" on her proposed Brexit deal.

While he didn't specify exactly what the referendum would involve, a second public vote would probably include the option of cancelling Brexit entirely and staying in the EU.

Mr Shuker is one of eight ex-Labour MPs in the new Independent Group. They are joined by three former Conservative MPs.

Conservatives do not have a majority in the House of Commons, but Theresa May remains in power thanks to a deal with the DUP, which has 10 MPs and represents seats in Northern Ireland.

The Independent Group now has 11 MPs, more than the DUP.

Mr Shuker said they could offer Mrs May a "confidence and supply" deal. This means voting to support the Government in votes of confidence, so that it can stay in power, and voting for legislation related to the Budget and taxation.

He revealed the plan in an interview with website HuffPost - and said he first offered the deal to Tory Cabinet Minister David Liddington in January, when Mr Shuker was still a Labour MP.

Mr Shuker told Huffington Post: “I went into the Cabinet Office about a month ago when Theresa May was in full listening mode and sat down with David Lidington when I was a Labour MP and I said, look you can have my support to pass any deal you like on Brexit – it can be Norway, it can be Theresa May’s deal, it can be Canada, whatever you want you can have my vote.

“But at the end of it I want a confirmatory referendum.

“And do you know what? If you do that British politics is going to be shaken quite a bit if you get that through – I’m willing to extend confidence and supply to your government so it doesn’t fall over through the period of the referendum. If it’s a year, fine.”

The Independent Group press conference: Luciana Berge, Chuka Umunna, Ann Coffey, Gavin Shuker, Mike Gapes, Angela Smith and Chris Leslie
The Independent Group press conference: Luciana Berge, Chuka Umunna, Ann Coffey, Gavin Shuker, Mike Gapes, Angela Smith and Chris Leslie

Mr Shuker continued: “They obviously didn’t choose to go down that route.

“But if you are asking me about future hypotheticals about when the maths of parliament are so febrile, it comes down to – to use the cliche – doing the right thing by the country.”

He said the Government should agree to support a proposal from Labour MP Peter Kyle, who is calling for the House of Commons to support Theresa May's proposed Brexit withdrawal agreement if she agrees to hold a referendum.

Mr Shuker said: "In those circumstances I think the national interest would be served by seeing a period of stability to get that referendum done."

The comments are likely to be seized on by some Labour MPs and activists, who argue that The Independent Group will keep the Conservative Party in power.