Rival parties ramped up their campaigns to win over voters in key battlegrounds on Thursday, one day before early voting begins for the June 3 local elections and parliamentary by-elections.

South Korea's June 3 election race is heating up, with opinion polls hinting at closer-than-expected races in many key battlegrounds eyed by the ruling Democrat

Rival parties ramped up their campaigns to win over voters in key battlegrounds on Thursday, one day before early voting begins for the June 3 local elections and parliamentary…