Voting got underway Sunday in by-elections to fill two vacant seats in the Diet, with the result being closely watched as a bellwether of public support for Prime Minister Fumio Kishida and his Liberal Democratic Party ahead of next week's general election.

The House of Councilors by-elections in Shizuoka and Yamaguchi prefectures are the first national contests since Kishida took office earlier this month promising to implement a "new capitalism" that puts the country on a growth track while redistributing wealth to the middle class.

Media polls for the Oct. 31 general election have suggested that the LDP and its coalition partner, Komeito, will retain their majority in the House of Representatives, the more powerful lower chamber.