Jacob Rees-Mogg, Boris Johnson and Peter Bone at the launch of a plan for trade after Brexit. Mr Johnson claimed that adopting Theresa May’s Chequers proposal instead would result in “vassalage”

Hardline Conservative Brexiteers are struggling to persuade their colleagues to support their open defiance of Theresa May’s Chequers plan, sources have said.

Amid divisions on the right of the party over the approach to take to Chequers, a number of Brexit supporting backbenchers have distanced themselves from the hardline position being taken by the ultra Eurosceptic European Research Group.

One accused the group of taking a “nothing is ever quite enough” approach while several predicted the scale of opposition to any eventual deal would be far smaller than predicted by the ERG.

Steve Baker says 80 Tories would oppose Mrs May’s Chequers plan DARREN JACK/REX

On Monday Steve Baker, the former Brexit minister, said that 80 Tories would vote against a Chequers-style deal. Yesterday a number of pro-Brexit MPs told The Times that although they did not like