TOKYO (AP) — Japan’s Prime Minister Shigeru Ishiba announced Sunday he will step down following growing calls from his party to take responsibility for a historic defeat in July’s parliamentary election.

Ishiba, who took office in October, had resisted demands from mostly right-wing opponents within his own party for more than a month, saying such a step would cause a political vacuum when Japan faces key challenges in and outside the country.

The resignation came one day before his Liberal Democratic Party was to decide whether to hold an early leadership election, a virtual no-confidence motion against him if approved.

Ishiba said during a televised press conference he would start a process to hold a party leadership vote to choose his replacement and that there was no need for Monday’s decision.

If the prime minister had stayed on, he would have inevitably struggled to manage his divided party and minority government.

In July, Ishiba ’s ruling coalition failed to secure a majority in the 248-seat upper house in a crucial parliamentary election, further shaking the stability of his government. The loss added to an earlier election defeat in the lower house, where the party-led coalition also had lost a majority.