An estimated one million protesters have marched through London to demand a second referendum on Brexit, organisers said.
The demonstration calling for a Final Say on the crisis is believed to be one of the biggest marches in British history.
“The #PeoplesVoteMarch has today become one of the biggest public protests in British history,” a spokesperson for People’s Vote UK said on Twitter.
Demonstrators marched from Park Lane to Parliament Square, as MPs attended a spacial Saturday sitting of the Commons.
Many held banners calling for a fresh public vote with the option to Remain in the EU.
Supporters in Parliament Square have heard from speakers including Sadiq Khan, the mayor of London, Keir Starmer, the shadow Brexit secretary and the actor Patrick Stewart.
They will also hear from shadow chancellor John McDonnell.
“I’m proud to stand with hundreds of thousands of people in demanding that they, not wealthy, privileged and out-of-touch hard-right Tory MPs, have the final say on what is an even worse deal than Theresa May’s,” Mr McDonnell said ahead of the march.
“Our policy is clear: Let the people decide.”