Brexit 'People's Vote' march - live updates
As the speeches end and protesters file away from Parliament Square, here is a roundup of the day's main developments.
- Organizers claim that 1 million people took to the streets of the British capital today. CNN has not been able to verify this figure and London's Metropolitan Police are not commenting on crowd estimates.
- Prime Minister Theresa May came in for heavy criticism from speakers in Parliament Square at a time when she is already facing calls to resign.
- The UK is gearing up for another crucial week in the torturous Brexit process as the PM attempts to convince MPs to vote her deal through Parliament.
“It’s been over 10 years since I have been on a march," said Naomi Penfold, 29, from Cambridge.
"Normally Brits stay quiet and grumble but with Brexit there is too much at stake.”
Labour deputy leader Tom Watson has implored Theresa May to "have a look out of the window" and "look at this great crowd today" in a tweet following his speech in Parliament Square.
Former deputy prime minister Michael Heseltine criticized Theresa May in a speech in Parliament Square.
“The Prime Minister herself bears a heavy personal responsibility for our current crisis,” he said, adding that her criticism of MPs last Wednesday was an "affront to parliamentary democracy."
Generals who lose wars blame their troops, managers who break their companies blame the workers, said Heseltine.
"Now we can add: Prime ministers who lose elections blame their MPs," he said, before calling for a second referendum.
"One way or another, you the people must decide. You the people must be free to vote to remain."
Private equity director Jonty Graham, 35, and PR executive Charlotte Graham, 32, are attending the protest with their daughters Poppy, 5 and Tilly, 4.
"We are sleepwalking towards disaster," Jonty Graham told CNN.
"I have lots of friends who I play with who are French and Spanish and I like playing with them," said Tilly.
The Independent Group, a cross-party bloc of rebel anti-Brexit MPs, has posted a time-lapse video showing the crowd in Parliament Square.
MP Anna Soubry, who recently left the Conservative party to join a breakaway cross-party bloc known as the Independent Group, spoke to crowds in Parliament Square.
In a video posted on Twitter by Independent Group MP Chris Leslie, Soubry said former Conservative colleagues have told her in private that they know a so-called "people's vote" is the only solution.
"Put your country first," she said, urging MPs to support a second referendum.
London Mayor Sadiq Khan addressed the crowds in Parliament Square this afternoon, and also called for a People's Vote on Twitter.
Take a look at a few of these protest signs for a bit of light relief.