Tens of thousands of protesters gathered in central London on Saturday to call for a new referendum on the United Kingdom's departure from the European Union. London Mayor Sadiq Khan was among those set to address the People's Vote March, which culminates at a rally in Parliament Square. Gina Miller, who successfully took the UK government to court to force the prime minister to seek parliamentary approval for leaving the European Union, said the people had a democratic right to voice their criticism of the Brexit process. Organizers want the public to have a final say on the government's Brexit deal with the EU, arguing that new facts have come to light about the costs and complexity of Britain's exit from the bloc since Britons voted to leave in 2016. (AP)