Voting was underway Sunday in by-elections to fill two vacant seats in parliament, with Prime Minister Fumio Kishida's Liberal Democratic Party facing off against the leading opposition force in one-on-one battles.

The by-elections for the House of Representatives, the more powerful lower chamber, and the House of Councilors are the first national contests since Kishida revamped his Cabinet last month in a bid to bolster his government.

The conservative LDP is aiming to retain the seats as Kishida struggles to shore up his Cabinet's approval ratings, which have plunged to their lowest levels since he assumed power in October 2021.