Eurosceptic backbencher Jacob Rees-Mogg has delivered another ultimatum to Theresa May, warning of outright rebellion among his colleagues unless the Prime Minister delivers the Brexit she promised from the outset.
The arch Brexiter and leader of the European Research Group has warned that Conservative MPs would vote against the final withdrawal agreement if the UK does not make a clean break from the EU.
In article for The Telegraph, he wrote: “The Prime Minister must stick to her righteous cause and deliver what she has said she would, she must use her undoubted grace to persevere."
As previously revealed by City A.M., the Prime Minister is preparing for a "third way" option on the customs union, which would build heavily on the max fac option that has emerged as the stronger contender than the alternative new customs partnership.
This is likely to result in "the softest of hard Brexits", sources suggest.
But Rees-Mogg has warned against any betrayal of the negotiation red lines May had previously set out, branding the new customs partnership "idiotic".
He added: "Any attempt by the EU to impose its laws and court on the UK, either directly or indirectly, must be rejected.
“Any EU agreement that restricts the country's ability to make trade agreements with other states, restricts our ability to control our migration policy makes us pay to trade or interferes with our fishing waters could not be accepted.
“Indeed MPs would vote against such propositions in Parliament."
But Rees-Mogg has been slapped down by not one but two ministers. Alistair Burt and Sir Alan Duncan, both Foreign Office ministers, have publicly criticised the MP.
Burt tweeted: "Enough. Just tired of this endless threat and counter threat. Why don’t we want the best for the U.K. than for our own ideological cliques? And there are others in this negotiation as far as I’m aware?"
Duncan added: "Rees-Mogg’s insolence @Telegraph in lecturing & threatening PM is just too much. Risks debasing govt, party, country & himself. PM must be given maximum latitude & backing. The ideological right are a minority despite their noise & should pipe down. twitter.com/hashtag/totalsupportforMay?src=hash">
Separately Olly Robbins - May's key Brexit negotiator - has been warning ministers ahead of the Chequers summit not to expect a bespoke deal. During a Cabinet briefing, Robbins suggested a Norway-style system was the most likely outcome.
The standoff comes after 36 Tory MPs called on the Prime Minister to "get tough" with the European Union in an open letter.
The group, led by Andrea Jenkyns - who quit the Government in May, wrote: "We must not remain entangled with the EU’s institutions if this restricts our ability to exercise our sovereignty as an independent nation.
"Anything less will be a weakening of our democracy. Britain must stand firm."