The five constituencies are Suwon and Ansan in Gyeonggi Province; Gangneung in Gangwon Province; the region covering Jeungpyeong, Jincheon, Goesan and Eumseong in North Chungcheong Province; and Yangsan in South Gyeongsang Province.

They will be the first elections held in all provinces excluding Jeolla and Jeju since the launch of the Lee Myung-bak administration.

Since the by-elections are a precursor to the local elections in June next year, today’s vote will likely have a huge impact on party dynamics. They will also likely affect pending issues such as the dispute over the Sejong City administrative region.

The voting will run from 6 a.m. to 8 p.m. The National Election Commission said preliminary results will come out around 11 p.m.

Ruling Grand National Party Chairman Chung Mong-joon said in a statement to the people, “Please support the ruling party for stable administrative management.”

Main opposition Democratic Party leader Chung Sye-kyun said, “These by-elections must serve as an opportunity to judge the mistakes of the ruling party.”

Minor conservative Liberty Forward Party chief Lee Hoi-chang said, “The Liberty Forward Party is the only party that represents the Chungcheong provinces.”