A Conservative Party investigation into Boris Johnson is a “show trial” and is being used to stop him becoming leader, Jacob Rees-Mogg has claimed.
Writing in the Daily Telegraph, the Tory backbencher blamed Theresa May’s “personal rivalry” with Mr Johnson for “taking the heat off Labour”.
A Downing Street source told the BBC the investigation was “not about individuals or personalities”.
Mr Johnson said women in burkas looked like “letter boxes” or “bank robbers”.
His remarks – in a Daily Telegraph column last week – have been called Islamophobic and the Tory Party received dozens of complaints.
The former foreign secretary, who also argued against a ban on full-face veils, has rejected calls to apologise.
Mr Rees-Mogg said it was “hard to see” how Mr Johnson had breached the party’s code.
The Downing Street source said the party has to investigate any complaint.
The complaints will be looked at by an independent panel which could refer Mr Johnson to the party’s board – it has the power to expel him.
In a column in the Telegraph newspaper on Saturday, Mr Rees-Mogg said he “entirely agrees” with Mr Johnson over the issue and made clear that he also does not support a ban on the burka.
He suggested that senior conservatives have attacked Mr Johnson because of “envy” of his “many successes, popularity with voters and charisma”.
The North East Somerset MP wrote: “Could it be that there is a nervousness that a once and probably future leadership contender is becoming too popular and needs to be stopped?
“This may explain the attempt to use the Conservative Party’s disciplinary procedures, but it has been handled so ham-fistedly that it brings only sympathy and support for Mr Johnson,” he wrote.
Mr Rees-Mogg – who is a leading Brexiteer and has previously criticised the prime minister – said it would be “absurd” to call Mr Johnson’s remarks “either victimising or harassing” and it was “hard to see” how Mr Johnson could have broken the party’s code of conduct.
He wrote: “When Margaret Thatcher was leader, she and Michael Heseltine were hardly soulmates, but she would not have allowed personal rivalry to take the heat off the Labour Party… nor would she have countenanced any attempt to have a show trial.
“Attacking Boris merely helps the opposition.”
On Friday, the UK’s equalities watchdog said Mr Johnson’s remarks were “inflammatory and divisive” and his comments risked “vilifying Muslim women”.
Conservative Party chairman Brandon Lewis and leader Theresa May have both called on Mr Johnson to apologise for his comments.
The founder of the Conservative Muslim Forum, Lord Sheikh, has written to Mr Lewis demanding “serious action”, while former attorney general Dominic Grieve said he would quit the party if Mr Johnson became prime minister.
But comedian Rowan Atkinson was among those who expressed support for Mr Johnson.
The Telegraph newspaper said it had been “inundated” with letters in support of Mr Johnson and gave over its whole letters page to publish them.
Mr Johnson is on holiday abroad and is yet to respond to the reaction to his article.
A panel will look into the complaints against Mr Johnson’s comments. The head of the panel can dismiss the complaints if they are found to be obviously trivial, lacking in merit or unable to be fairly investigated.