Police in Sadiq Khan’s London have used the Public Order Act to prevent a march in support of U.S. President Donald Trump from the American embassy, despite permitting large, ill-tempered anti-Trump marches on Friday.

Protestors attending the ‘Welcome Trump’ event had planned to gather outside the embassy and march from there to Whitehall, where they would have joined in with a separate ‘Free Tommy Robinson’ event in support of the activist and independent journalist who was recently imprisoned for contempt of court after reporting on a grooming gang trial.

But the Metropolitan Police Force, which answers to a large extent to Mayor of London Sadiq Khan, used the Public Order Act to impose a raft of restrictions on both groups of protesters which made this impossible — despite allowing far larger anti-Trump protests at which at least six people were arrested to go ahead the day before, with demonstrators carrying signs emblazoned with harsh profanity and messages such as “Die Trump Die”.

The Police have slapped Section 12 of the Public Order Act on the pro-Trump rally at the US Embassy. Here’s @davidkurten and @ReeceUKIP with the news. pic.twitter.com/qz7MRIfGRe — UKIP (@UKIP) July 14, 2018

“I was planning to go to the American embassy to meet with a group of demonstrators who are planning to welcome Trump into the country… it’s really good to see him in this country, and speaking truth to the people in power in this country,” explained David Kurten, an elected member of the London Assembly for the Brexit-supporting UK Independence Party.

“But as I came out of the police station I was handed this piece of paper by a couple of friendly police officers, who were just doing their job, but they’ve imposed Section 12 Public Order Act conditions on the assembly outside the American embassy, which means that people are not allowed to proceed or have a march or any kind of demonstration,” he claimed.

“And we’ve also been told that if I go to the American embassy in a group of three or more people that I’m liable to be arrested myself — so free speech is dead,” he concluded.

“What this is, is Sadiq Khan not wanting people to express pro-Trump values,” added Young Independence Deputy Chairman Reece Coombes.

“But as soon as probably only a few thousand of us want to protest in favour of Trump and show our support for the leader of the free world, we are banned, we are silenced, and we are censored.”

Mayor Khan actively encouraged the anti-Trump protests, and was active in the media defending his decision to authorise an “obscene” balloon caricaturing the U.S. President on grounds of freedom of speech and the right to protest.

The restrictions on the ‘Welcome Trump’ event are only the latest example of what critics have described as double standards in this area, with the Mayor having previously provided almost £2 million in funding for an “online hate crime hub” for police to tackle mean comments on the Internet, and banned fitness supplement adverts featuring attractive women from the London Underground.

Follow Jack Montgomery on Twitter: @JackBMontgomery