Thousands of demonstrators gathered in central London on Saturday to march in protest against last week's vote to leave the European Union, a result that has plunged Britain into political chaos and which most people in the capital rejected.
Most protesters were young adults, and many were draped in EU flags while others waved banners proclaiming slogans like "I'm with EU" or simply "Wrexit."
They chanted "What do we want to do? Stay in the EU," as they set off for the Westminster political district.
"I was genuinely stunned on the morning after the vote," said one marcher, Nathaniel Samson, 25, from Hertfordshire, north of London.
"I feel deeply uncertain about my future," he added. "I'm on the march to voice my discontentment. I am accepting the result, but it's to show that we won't accept it quietly."
London voted 60 percent in favor of remaining in the EU in the June 23 referendum, with younger voters widely in favor of staying in the bloc, but 52 percent of Britons overall cast ballots in favor of leaving.
Rally organizer, King's College graduate Kieran MacDermott, said: "We can prevent Brexit by refusing to accept the referendum as the final say and take our finger off the self-destruct button."
Parliament should have the final say on whether Britain should leave, he told the BBC.
The vote to leave has prompted a battle within the ruling Conservative Party to succeed Prime Minister David Cameron who said he would resign after the result.
The main opposition Labour Party has also turned on itself, with most of its lawmakers in parliament having voted to withdraw support for party leader Jeremy Corbyn after what they saw as his lackluster contribution to the referendum campaign.