Donald Trump says he "used to love London" but that the persistent protests against him - culminating in the 20-foot blimp of the president as a screaming, small-handed baby which will fly above Parliament Square this weekend - have put him off visiting.

"I guess when they put out blimps to make me feel unwelcome, no reason for me to go to London," he told the Sun.

"I used to love London as a city. I haven’t been there in a long time. But when they make you feel unwelcome, why would I stay there?"

What could possibly have turned the people of London against him? Could it be his persistent antipathy toward London Mayor Sadiq Khan, who he claimed in the Sun interview was doing "a terrible job" and, in particular, had "done a very bad job on terrorism".

Khan's poll numbers have slipped slightly in the last year - 52 percent said he was doing a good job in a YouGov poll from April this year, compared to 61 percent the previous April - but they remain better than Trump's, whose approval ratings in America average roughly 42 percent.

In a city in which a quarter of the workforce was born outside of the UK, Trump's anti-immigration rhetoric has a lot to do with it too, and he doubled down on the theme while talking to the Sun.

"I think allowing millions and millions of people to come into Europe is very, very sad."

"I look at cities in Europe, and I can be specific if you’d like. You have a mayor who has done a terrible job in London. He has done a terrible job."