A makeshift beach was set up by protesters on the doorstep of the French embassy in central London on Thursday after several coastal towns in France imposed a ban on the burkini, a swimsuit that covers the whole body.
Several demonstrators at the protest – which was open to women only and organised by campaigners on Facebook – said the ban is "anti-women and Islamophobic".
Around 100 campaigners, supporters, and onlookers gathered outside the embassy as children and women dressed in burkinis, bikinis, and other beachwear items played in the sand for around an hour.
Some women had travelled from across the UK, including from Brighton and Whitstable, to be at the protest.
Earlier this week photos of a woman in Nice being ordered to take her clothes off by armed police went viral.
The images prompted an outcry across the world, and many people pointed to the "hypocrisy" of the ban.
France's highest administrative court examined a request to overturn the ban on the burkini on Thursday. A decision is expected to be made on Friday afternoon.
On Thursday morning, London mayor Sadiq Khan condemned France's burkini ban as he met with his Parisian counterpart, Anne Hidalgo, for talks on how to improve community integration.
One protester at the event in London, Jenny Dawkins, a curate at a church in Peckham, said the ban on the burkini was "setting a group of women apart who already feel isolated and threatened".
"I'm shocked by what Muslim women have had to go through," she told BuzzFeed News. "This law isn't about clothing, it's about something different – you have to look at the image: a woman being stood over and told to dress in a different way by men carrying weapons... There's no context in which that's right."
Aina Khan, a protester who lives in London, said that as well as being an attack on women, the burkini ban was rooted in Islamophobia.
She said Islamophobia as an issue had not been fully addressed "within the non-Muslim and white feminist community". Despite this, she hoped the protest would help begin a conversation as to why Muslim women are being targeted.