South Korea's Democratic Party of Korea is heading into the June 3 local and parliamentary by-elections in a commanding position, with President Lee Jae-myung's approval rating standing at 59.8 per cent in the latest Real Meter survey and analysts projecting the ruling bloc to capture at least 15 of 17 metropolitan and provincial governorships.
The vote will fill governor and mayoral posts across the country, including in the heavily contested cities of Seoul and Busan, alongside thousands of council seats. Parallel by-elections will fill 14 vacant National Assembly seats, several of them held by senior figures.
For the conservative People Power Party, retaining strongholds in Daegu and parts of the south-east is seen as essential to halting a slide that began with last year's presidential defeat. Internal party polling indicates the gap with the Democrats has narrowed in some battleground cities since April but remains in double digits in most.
Recent controversies surrounding Democratic Party chair Jung Chung-rae have provided the only concerted attack line for the opposition. The party leader was filmed in Busan on May 3 prompting a young child to address a male candidate using a term of endearment, drawing criticism from civic groups and competing politicians.
Campaign issues have been dominated by housing prices in the capital area, the future of South Korea's nuclear-export programme and cost-of-living pressures. The Lee administration says its first-year package of welfare and small-business measures has begun to feed through to households.
Final pre-election polls are expected over the May 17 weekend before a statutory blackout takes effect on May 28.