The dismal results underscored deepening distrust in the ruling Liberal Democratic Party due to a slush funds scandal, signaling a seismic shift in the support that enabled it to return to power in 2012 after a spell in opposition.

The coalition would still fall short of a majority in the powerful lower house even if Ishiba accepts back into the LDP former party lawmakers who ran as independents after being denied LDP endorsement over the scandal. The party fell short of 200 seats in the 465-member chamber.