Anti-Brexit remain in the European Union supporters hold a placard showing current Prime Minister Boris Johnson portrayed as the Joker as they take part in a "People’s Vote" protest march calling for another referendum on Britain’s EU membership, in London, Saturday, Oct. 19, 2019. Britain’s Parliament is set to vote in a rare Saturday sitting on Prime Minister Boris Johnson’s new deal with the European Union, a decisive moment in the prolonged bid to end the Brexit stalemate. Various scenarios may be put in motion by the vote. (AP Photo/Matt Dunham)