Former foreign secretary Boris Johnson is known for his bombast and provocative stunts. (Toby Melville/Reuters)

Former British foreign secretary Boris Johnson will face an internal investigation over complaints that he violated the ruling Conservative Party’s code of conduct when he wrote in a newspaper column last week that women in burqas resemble “bank robbers” and “letter boxes.”

Johnson resigned as Britain’s top diplomat a month ago after claiming that Prime Minister Theresa May’s proposals for a soft exit from the European Union were killing the dream of a clear, decisive split from the bloc.

Johnson remains a backbench member of Parliament and a contender to replace May in a future contest for power. After quitting his cabinet post, the flamboyant former mayor of London took up his pen again as a paid opinion writer for the Daily Telegraph.

His most recent column noted his opposition to a new ban on face veils in Denmark but veered away to critique traditional Islamic garb, calling niqabs and burqas “oppressive and ridiculous.” 

Johnson asserted that schools should be entitled to tell a student to remove a veil if the person “turns up . . . looking like a bank robber.”

“It is absolutely ridiculous,” he wrote, “that people should choose to go around looking like letter boxes; and I thoroughly dislike any attempt by any — invariably male — government to encourage such demonstrations of ‘modesty.’ ” 

The Boris Burqa Brawl quickly ensued on social media.

Johnson was called upon to apologize but declined, according to his employers. He is believed to be on vacation and has not been heard from.

While Johnson and the Conservatives face allegations of stoking “Islamophobia,” the Labour Party and its leader, Jeremy Corbyn, also stand accused of condoning anti-Semitism among party members.

Critics said it was outrageous that a Conservative aspirant to top office and Britain’s former face to the world would launch such a broadside against traditional Islamic attire.

The streets of London are filled with women wearing face veils, some of them visitors to pricey shopping districts, others British citizens. About 5 percent of the British population is Muslim, mostly from Pakistan and Bangladesh.

David Lammy, a member of the opposition Labour Party, called Johnson a dime-store version of President Trump and said he was “fanning the flames of Islamophobia” for political gain.

Johnson is known for his bombast, elocution, gaffes and provocative stunts, but even a few fellow Tories said he had gone too far this time.

May said his words “clearly caused offense . . . and I do think that we all have to be very careful about the language and terms we use.”

Culture Secretary Jeremy Wright said it was reasonable to have “a robust conversation” about the wearing of veils but that he did not like Johnson’s tone. 

“We’re not talking to our friends in the pub. We are public figures, and we have an additional obligation to be careful,” Wright told the BBC

The leader of the Scottish Conservatives, Ruth Davidson, called Johnson’s remarks “gratuitously offensive” and said he should apologize.

Jacob Rees-Mogg, a Conservative member of Parliament, however, told Nigel Farage on his radio show on Thursday that May was wrong. “He’s completely entitled to say it, and there’s nothing to apologize for,” said Rees-Mogg, who — like Johnson and Farage — favors a hard and fast Brexit.

Metropolitan Police Commissioner Cressida Dick, who had tasked officers to look into the matter, told the Telegraph that Johnson’s words “did not meet the threshold for a criminal offense.”

Conservative lawmaker Conor Burns criticized the police scrutiny. “With everything else going on in London, to be diverting resources into an even cursory investigation into an article is bizarre,” he told the newspaper.

Longtime Johnson watchers suggest that he is modeling his rhetoric on Trump and seeking to bolster support among right-wing Conservative supporters.

Baroness Sayeeda Warsi, a member of the House of Lords and a Conservative, tweeted, “Boris is merely a symptom, the disease of Islamophobia runs far deeper.” She said she welcomed an investigation, “but let’s not pretend this is an isolated incident.”