Theresa May has been unable to contain Brexiteer anger over her “turd” Brexit proposals, with backbenchers reportedly moving to trigger a vote of no confidence in her leadership.

Left-liberal news anchor and political insider Robert Peston cited sources confirming formal letters calling for a confidence vote are being sent to Graham Brady, who chairs the 1922 committee of Tory MPs who do not hold government positions.

According to the ITV host, the letters appear to be a “spontaneous” response to the Prime Minister “traducing those who voted to leave [the] EU” rather than a concerted effort by Jacob Rees-Mogg — the party’s leading backbench Brexiteer — and his European Research Group faction.

Sources confirm letters calling for vote of confidence in @theresa_may leadership going in to @Graham__Brady, chair of 1922. Tory Brexiters very unhappy – accuse PM of traducing those who voted to leave EU. This appears to be spontaneous, not coralled by ERG & @Jacob_Rees_Mogg — Robert Peston (@Peston) July 8, 2018

Plans to rebel were initially reported by The Sunday Times, with backbenchers unable to stomach May’s ‘Brexit’ proposals — which would see Britain effectively remain inside the Single Market for both goods and agri-products and submit to a “common rulebook” dictated by the European Court of Justice, as well as a host of commitments to match EU rules on state aid, environmental policy, social policy, and more.

Details of the proposals were reportedly submitted to Germany’s Angela Merkel before May hashed them out with her own Cabinet at an away-day in the prime ministerial countryside retreat of Chequers.

Foreign and Commonwealth Secretary Boris Johnson, who is probably the Cabinet’s most senior Brexit supporter, is said to have branded the plan “a big turd” at the meeting, and warned that anyone supporting it would be “polishing a turd”.

He did not immediately resign over the proposals, however — and several Brexiteer MPs have told him he has just 48 hours to do so if he wants their support as May’s replacement.

Other backbenchers have backed the aforementioned Jacob Rees-Mogg, with one describing the Somerset MP as “our Churchill”.

"I will not vote for something that doesn't deliver Brexit" says @Jacob_Rees_Mogg pic.twitter.com/WjE9OTn1tc — BrexitCentral (@BrexitCentral) July 7, 2018

Rees-Mogg has indicated he will not support a deal which does not deliver Brexit.

“An egg which is very softly boiled isn’t boiled at all; a very soft Brexit means we haven’t left, we’re simply a rule-taker,” he observed.

“That is not something that this country voted for; it’s not what the Prime Minister promised… I will certainly stick to the Conservatives’ manifesto commitments, and will not vote for something that doesn’t deliver Brexit.

Follow Jack Montgomery on Twitter: @JackBMontgomery