TOKYO — Japan’s Liberal Democratic Party and its ruling coalition partner, Komeito, lost their majority in the lower house of parliament for the first time since 2009 in Sunday’s general election, casting uncertainty over the future of Prime Minister Shigeru Ishiba’s government less than a month after he took office.

The LDPled by Ishibaand combined Komeito won a 215 seats by Nikkei’s count, falling short of the 233 needed to maintain a majority in the 465-seat chamber. The opposition parties secured 235 seats. Both sides are expected to start a scramble to put together a majority coalition to form a government.