The letter, revealed by the Times tonight, urged Theresa May to stick to the Brexit ideals outlined in her rousing Lancaster House speech one year ago.
The Tory MPs offered their “continued and strong” support for Mrs May’s leadership before strongly suggesting six ways in which the PM could strengthen the country’s position.
The letter was written by former Remainer John Penrose and signed by another 61 MPs, including hardline Brexiteer Mr Rees-Mogg, former cabinet member Priti Patel and former party leader Iain Duncan Smith.
The letter, which is date-stamped February 16 and has been shared on social media tonight, emphasised the group’s support for leaving both the EU customs union and single market – before pointedly offering “suggestions” on how Mrs May could achieve her goals.
The letter concluded with another declaration of support for the PM.
It said: “Famously you said that you wanted to make a success of Brexit. We wholeheartedly agree with you.
“Only a Conservative Government led by you can deliver these opportunities for our country.”
One Tory MP responded with fury to the letter.
Stephen Hammond, who supported Remain, told the Times:“The PM must not be constrained in the upcoming negotiations.
“Any restraint on what the government does during the transition period must be resisted.
“If it is in the UK’s interest to remain aligned to international and EU standards to allow trade it would be madness not to do so.”