A “Brexit betrayal” march led by controversial activist Tommy Robinson was “vastly” outnumbered by counter-demonstrators, opposition organisers said.
The English Defence League (EDL) founder turned-Ukip adviser marched with supporters through the streets of London on Sunday before addressing a rally beside Parliament Square.
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.
Labour grassroots group Momentum said about 15,000 turned up to oppose Mr Robinson’s march, claiming opponents “vastly” outnumbered the Ukip-led demonstrators nearly five to one.
A Ukip spokesman said “quite a few thousand” had turned up to its rally, which came ahead of MPs voting on a Brexit deal on Tuesday.
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.”