Undecided voters are key target on eve of British election

Conservative Party supporters react during a final general election campaign event in London, Britain, December 11, 2019. (Photos: Agencies)

Britain's opposition Labour Party leader Jeremy Corbyn waves during a final general election campaign event in London, Britain, December 11, 2019.

Britain's Prime Minister Boris Johnson speaks during a final general election campaign event in London, Britain, December 11, 2019.