One man, who gave his name as Laukan Creasey, even brought along his own home-made gallows.
When asked by a photographer, Sam Blewett, what it was for, he said: “That’s what the traitor May deserves. That’s what treasonous people get.
“It was a referendum not a never-endum. And they promised to implement whatever we decided and they haven’t, so two-and-a-half years down the line this is what you get.”
Elsewhere, the FT’s Sebastian Payne quoted Ukip spokesman Paul Oakley using an interesting film analogy.
He said: ”Beware Remoaners, our strength and courage comes from The Terminator. We can’t be bargained or reasoned with.
“We will absolutely never stop ever until we get hard Brexit.”
And one participant was holding a sign saying “Jo Cox False Flag”, suggesting the murder of the Labour MP in 2016 was part of an unspecified conspiracy.
Amid fears of violence, Scotland Yard placed restrictions on the march as well as on a counter-demonstration organised by Labour supporters and anti-fascists.
Among those marching against the Brexit betrayal group were Labour grassroots group Momentum and Unite Against Fascism.
A Momentum spokeswoman said about 15,000 turned up to oppose Robinson’s march, claiming it “vastly” outnumbered them nearly five to one.
And in a video posted to twitter, Journalist Owen Jones branded it a “total and utter humiliation” for Robinson.
A Ukip spokesman said “quite a few thousand” had turned up to its rally. Police did not provide estimates on crowd sizes.
Momentum national co-ordinator Laura Parker said: “Today is a huge blow for Tommy Robinson and his vile, hate-fuelled politics.
“Even with the Ukip machine in tow he only managed to bring a few thousand supporters out on the streets while we mobilised nearly 15,000 to march against his racism and bigotry.”
Robinson’s supporters gathered to call for Brexit, with one brandishing a noose he said was for Prime Minister Theresa May.
Shadow chancellor John McDonnell had urged Labour supporters to march against the “poison” of Robinson, whose real name is Stephen Yaxley-Lennon.
“This march isn’t about Brexit, it’s about far-right extremists dressing up in suits and pretending to be respectable,” McDonnell said.
Along the route, the counter-protest included songs and dancing, arriving at their final stop on Whitehall to the sound of Michael Jackson’s hit Black Or White.
As the demonstrators made their way from Portland Place, they held placards saying: “Oppose Tommy Robinson. Don’t let the racists divide us” and chanted “There are many many more of us than you”.
Marchers with their faces covered briefly made their way to the front of the march, and at a few points a handful of Robinson supporters were escorted away swiftly by police.
The protesters chanted the whole way, shouting “Nazi scum, off our streets”.
Gathering outside the Dorchester Hotel, Robinson’s supporters marched along a specified route from Park Lane to Parliament Street.