Cocoa Laney, a documentary photographer, wanted to capture more than just pictures at the demonstration, which brought a claimed one million protesters to central London.
She asked each photographed protester to write a letter to the prime minister.
As little as two words, for some, were enough: "Do better!!"
Some of the her subjects were children, who wrote longer missives.
“All of my friends and family are part-European,” one youngster wrote to the UK’s leader. “Do you want to ruin this?”
The Put it to the People march is thought to have been one of the biggest protests in the UK’s history, with most attendees demanding a second referendum on Brexit and for the public to have the Final Say.
An online petition to revoke Article 50 and cancel Brexit has also been signed more than five million times, putting further pressure on Theresa May, who has struggled to maintain cabinet and party unity in the midst of the crisis.
For more of Cocoa Laney’s work you can visit her website here