A small crowd gathered in Westminster to watch the 29ft blimp take to the skies on Saturday morning.
As the inflatable went up, there were chants of “higher, higher, higher”.
Organisers say the stunt has helped them raise £58,000 for an ongoing campaign to remove Mr Khan from his post – because they say they blame him personally for a rise in violence in the capital.
“Under Sadiq Khan, we have seen crime skyrocket to unprecedented levels,” a statement on the crowdfunding web page states. “People in London don’t feel safe and they aren’t.”
It comes just a couple of months after the mayor waved through the flying of a blimp of Donald Trump during the US president’s visit to the UK.
Speaking on Saturday morning, lead organiser Yanny Bruere – a 28-year-old sales manager from Northampton – said it was done “in retaliation” to that particular stunt.
He said: “I think a certain amount of respect should be afforded to the leader of the free world and the greatest ally the UK has, the president of America.
“Obviously a lot of people feel the same, that Sadiq Khan doesn’t represent them and doesn’t speak for them and obviously they all want to see Sadiq Khan on a giant blimp as well.”
But the London mayor himself appeared relaxed about the whole affair.
“If people want to spend their Saturday looking at me in a yellow bikini they’re welcome to do so,” he told ITV London. “I don’t really think yellow’s my colour though.”
The yellow bikini references a decision by the Labour mayor to ban adverts which might create body confidence issues on Transport For London networks. That ban came into place after controversy over a protein shake poster which featured a model posing in yellow swimwear and asked, “Are you beach body ready?”
Spectators at Saturday’s event said they were concerned about freedom of speech issues, as well as crime.
One, Martin Daubney, 48, from southeast London, told the Evening Standard: “This is a bit of fun but I think Sadiq Khan has been a terrible mayor for London. I’ve lived here for 25 years and the feeling of impending crime on the streets has never been worse.”
But others have questioned the motives of the stunt.
Writing on Twitter, Labour MP Wes Streeting said: “Sadiq absolutely right to allow this – freedom to protest peacefully is vital to democracy. But people should see it for what it is – it’s not about policy, it’s a protest by those with links to far-right extremists that others have fallen for.”
On Friday, The Independent reported that organiser Mr Bruere had previously sent antisemetic tweets from a now deleted account.
Among his posts, he said Zionists had been responsible for immigration into Europe. But, when asked about the tweets on Saturday, he said they had been taken out of context and that he was pro-Israel.
He added that he is now considering taking the huge balloon across the country – although it remains unclear why he feels people outside of London would have especially strong views on the city’s mayor.
A spokesman for the mayor of London said on Friday: “The City Hall ‘city operations’ team has spoken with the organisers of this balloon and given permission for them to use Parliament Square Garden.”
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