TOKYO -- Japanese Prime Minister Shigeru Ishiba has expressed his intention to resign in order to avoid further division within the Liberal Democratic Party (LDP), national broadcaster NHK reported Sunday.

The decision comes just one day before the party is set to determine on Sept 8 whether to hold an extraordinary presidential election amid mounting calls for Ishiba to step down.

Ishiba is scheduled to hold a press conference at 6:00 pm local time on Sunday.

Within the LDP, 130 of the party's 295 Diet members are said to support holding an emergency leadership contest. Among them are senior figures as well as members of Ishiba's own cabinet, according to the NHK.

At the prefectural level, 18 of the 47 local chapters have already formally backed holding the election, with two more moving in that direction.

If more than half of the combined votes of lawmakers and prefectural representatives are secured, the contest will be triggered.

In postwar Japan, the president of the LDP, the dominant political force since its founding in 1955, almost always becomes the country's prime minister, since the party commands the largest bloc of seats in the Diet.

When an LDP president resigns or is replaced, the prime ministership typically changes hands as well.

In a landmark political setback in July, Japan's ruling coalition lost its majority in the House of Councillors, signaling deep public dissatisfaction with the government.

The defeat follows a similar outcome in the 2024 House of Representatives election, leaving the ruling bloc a minority in both chambers of the parliament, a historic first since the LDP's founding in 1955.