TOKYO (Kyodo) -- Japan's House of Councillors election will likely be held on July 13, given the envisaged Jan. 21 start of a parliamentary session, administration officials said Friday, in what would be the first nationwide poll for Prime Minister Shigeru Ishiba as head of a minority government.

Under this scenario, a 150-day parliamentary session is expected to run from Jan. 21 to June 19 with no extension, followed by a campaigning period for the upper house likely starting on June 26.

An election must be held before July 28, when the current six-year terms for half of the upper house members end.

Depending on how Diet deliberations proceed during the upcoming session, the timing of the election may change as Ishiba needs to take heed of more demands from an emboldened opposition bloc following the Oct. 27 general election.

While the Liberal Democratic Party and the Komeito party lost their majority in the powerful House of Representatives, or lower house, the ruling camp still controls the upper house.

After the expected enactment of a supplementary budget for the current fiscal year to next March to fund inflation-relief measures, the current extraordinary Diet session is expected to end on Dec. 21.

The regular session from January will see deliberations on a to-be-compiled state budget for fiscal 2025 from April.

Next year's election for the Tokyo metropolitan assembly, likely in late June, is seen as a barometer for what to expect in the upper house race.

While the government and the ruling coalition are now inclined toward the Jan. 21 start of the Diet session, they could still take time to decide on the exact date for the election, likely a Sunday.

If July 13 is dropped, July 27 will be the next most probable date, according to the officials, as the government and the ruling camp would avoid July 20, the middle of a three-day weekend.