Ultra-Remain Tory MPs are threatening to resign from the Conservative Party if the Government shifts its main focus to planning for a No Deal Brexit.

With only 100 days to go until Brexit Day, the current moves to prepare for a clean break with the EU are seriously belated, and Cabinet heavyweights such as Chancellor of the Exchequer Philip “Remainer Phil” Hammond are accused of continuing to frustrate No Deal planning.

However, some of the Tory parliamentary party’s most vociferous anti-Brexiteers have now warned they will go rogue if No Deal is not abandoned altogether.

Leading the charge was Nick Boles, who is Parliament’s main voice for what critics have described as a “Norway Minus” Brexit — i.e. continuing subjection to the EU Free Movement regime and most aspects of the Single Market through membership of the European Economic Area (EEA), plus continued membership of the EU Customs Union.

“I accept that it is prudent for the government to get ready for all eventualities. But I owe my constituents and my colleagues total clarity about my position,” Boles announced on social media.

“If at any point between now and 29 March the government were to announce that ‘no-deal’ Brexit had become its policy, I would immediately resign the Conservative whip and vote in any way necessary to stop it from happening.”

You don’t deserve the voters of the good Royal Anglian constituency of Granthan & Stamford and they certainly don’t deserve you. Go now. https://t.co/hgSFW5eO0h — Rɪᴄʜᴀʀᴅ Kᴇᴍᴘ ⋁ (@COLRICHARDKEMP) December 18, 2018

Mr Boles was supported by Anna Soubry, a former industry minister who blamed EU regulations for preventing her from saving British steelworkers from redundancy, but campaigned fiercely for a Remain vote in the 2016 referendum on Britain’s membership of the European Union membership anyway.

Having lost that, Soubry stood, like Boles, on a Brexit manifesto in the 2017 snap election, claiming to have accepted the Leave vote and voicing opposition to a second referendum — but she has now performed a complete U-turn, becoming one of the most strident voices for a so-called “People’s Vote”.

“You, me and other moderate One Nation Tories,” she said in response to Boles’s threat to resign over No Deal Brexit. “Country must come before party allegiance”

The pair were then joined by Sarah Wollaston, who like Ms Soubry previously claimed to have accepted the result of the 2016 referendum.

“I could not remain a member of the Conservative Party if PM changed her main policy objective to delivering No Deal and No Transition,” she wrote.

“No responsible government could knowingly aim to inflict that kind of harm on the people & especially when we are so woefully unprepared.”

Sarah Wollaston used to understand that politicians' role in the Brexit process was to implement the result, not do everything in their power to overturn the result. She must realise that voters got it right the first time. pic.twitter.com/If9NdMYaxV — Change Britain (@Change_Britain) December 18, 2018

Boles, Soubry, and Wollaston all represent constituencies which voted to Leave the European Union.

Follow Jack Montgomery on Twitter: @JackBMontgomery