Ahead of his visit to Britain this week, President Donald Trump took a moment to undermine Prime Minister Theresa May by praising her rival Boris Johnson, who stepped down as foreign secretary on Monday over May’s plan to pursue close ties to the European Union even after Brexit.

“Boris Johnson is a friend of mine; he’s been very, very nice to me,” Trump said, apparently having forgotten or just never heard that Johnson had denounced him as “clearly out of his mind” in late 2015 when the then-candidate for the American presidency had demanded “a total and complete shutdown of Muslims entering the United States.”

“You can’t ban people going to the United States in that way, or indeed to any country,” Johnson, who was then London’s mayor, told a television crew two days after Trump first called for a ban on Muslims on December 7, 2015.

Referring to Trump’s subsequent claim that his ban was justified because immigrants had made parts of London off-limits to non-Muslims, including police officers, Johnson also said that Trump was “betraying a quite stupefying ignorance that makes him frankly unfit to hold the office of president of the United States.”

“I would invite him to come and see the whole of London and take him ’round the city,” Johnson added, “except that I wouldn’t want to expose Londoners to any unnecessary risk of meeting Donald Trump.”

Despite that criticism, Trump was apparently so convinced of the falsehood that parts of London are “no-go zones” for non-Muslims that he even repeated the claim to May when she visited the White House in 2017 to invite him to Britain. One witness to that conversation, May’s strategy director at the time, Chris Wilkins, later told Bloomberg News that the prime minister was forced to “correct him.”

On the eve of his visit, however, with mass protests planned in London, Trump has provoked so much outrage among Britons that he has succeeded in making the British capital effectively off-limits for himself. British and American officials have planned an itinerary that will keep Trump out of London for all but a few hours during his stay.

Britons promoting the protests objected to an alert issued by the U.S. Embassy in London, arguing that the demonstrations were not anti-American, but anti-Trump.

Having recently voiced support for far-right, anti-immigrant politicians in Germany who want to topple Chancellor Angela Merkel, Trump appears to also hold a grudge against May. The reason could be that May has rebuked him for bigotry on more than one occasion since.

In June 2017, when Trump was harshly critical of London’s current mayor, Sadiq Khan, in the wake of a terrorist attack on the city, May hesitated but eventually said, “I think Donald Trump was wrong in the things that he has said about Sadiq Khan.”

Last November, when Trump promoted three anti-Muslim video clips from a fringe group of British racists, May again spoke up, despite the risk of jeopardizing a trade deal with the U.S. to compensate for Brexit. “British people overwhelmingly reject the prejudiced rhetoric of the far right, which is the antithesis of the values this country represents, decency, tolerance and respect,” May said in a statement. “It is wrong for the president to have done this.”

Trump responded at the time by scolding May on Twitter, writing: “Don’t focus on me, focus on the destructive Radical Islamic Terrorism that is taking place within the United Kingdom. We are doing just fine!”

When he was asked this week by the Washington Post why he was so critical of May and Merkel, Trump suggested that it was because both leaders support the kind of multicultural living that is common in the United States. “Immigration is destroying Europe as we know it and it is very sad to be witness to what is happening,” the son of an immigrant from Scotland told the newspaper.

Top photo: At a NATO meeting in 2017, Boris Johnson, then Britain’s foreign secretary, joked with Donald Trump behind the back of Prime Minister Theresa May.