Hundreds of people put on high-visibility jackets in imitation of French protesters as they marched in central London against government cuts.
Organisers from The People’s Assembly Against Austerity described Saturday’s march as the arrival in the UK of the “yellow vests” movement that rocked France in November 2018.
They even brought two campaigners from across the Channel to seal the relationship.
But they are not the only group to claim the spirit of the yellow vests, with pro-Brexit demonstrators outside Parliament also putting on high-vis jackets.
So why are demonstrators battling over this symbol?
The French connection
“English people, you look good in yellow!” said a message on the jacket of Erick Simon.
He is one of the gilet jaunes, as they are known in France, who travelled from Normandy with fellow organiser, Laurie Martin.
Ms Martin said she came “to support the British because our demands are the same as those fighting austerity across Europe”.
Image caption French protesters Erick Simon and Laurie Martin wore messages of support
Many protesters said they had been inspired by events in France.
Kylie Crawley said she wanted to stand against cuts to services for her 17-year-old daughter, Kacee, who has Down’s syndrome.
“To me the French yellow vests were ordinary people wanting to get out and tell people how bad things had got and how they wanted change,” she said.
Image caption Kylie Crawley bought yellow vests online, including for daughter Kacee
Jim Scott, who got up at 04:00 GMT to travel from west Wales to the protest, said the vests had become a powerful “symbol for change”.
“They’re facing the same things in France: austerity, cuts to public services, expanding the gap between rich and poor. That’s how this movement has started.”
As the march began, one protester cried, “Let’s show the French what we can do!”
Image caption Jim Scott said the yellow vest was “a symbol for change”
Is it a right-wing or left-wing symbol?
Meanwhile, another group of protesters was outside Parliament, also in yellow vests.
They waved the union jack, burned EU flags and denounced “left-wing scum”. “We’re not far right, we’re just right,” they chanted.
Say what you really think pic.twitter.com/ojUlM4ORy5
— Daniel Sandford (@BBCDanielS) January 12, 2019
In France, Interior Minister Christophe Castaner has said violent far-right and far-left groups have both infiltrated the gilet jaunes protests.
But Tony Griffiths from the People’s Assembly, which organised the UK anti-austerity march,