Japanese opposition parties won all three by-elections for parliamentary seats in a blow for Prime Minister Yoshihide Suga, who must hold a general election within six months, the results showed on Monday.

The outcomes of Sunday's races, the first since Suga was inaugurated in September, bode ill for his ruling Liberal Democratic Party (LDP) as the country prepares for a general election that must be held by this autumn, Yonhap reported.

The victories of the three candidates all supported by the main opposition Constitutional Democratic Party (CDP) come amid Suga's much-criticized response to the Covid-19 pandemic and scandals in the LDP, which led to two of the three races.

"We humbly accept the voters' judgement. We would like to correct what needs to be corrected," Suga told reporters on Monday. The election results were "very harsh," Hakubun Shimomura, who leads LDP's policy research council, told media. Shimomura added the results showed people want the government to do a better job in responding to the pandemic.

The rollout of coronavirus vaccines began in mid-February, but its pace has been extremely slow. Only 0.7 percent of the population has been fully vaccinated as of Thursday, according to the prime minister's office.

Suga declared a third state of emergency in Tokyo and three western prefectures, urging bars and restaurants to refrain from serving alcohol and offering a karaoke service while pressing ahead with the Olympics despite experts' warning of the risk of the Games becoming a super-spreader event.

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