TOKYO - The election campaign for Japan's House of Councillors, or the upper house of the Diet, was officially launched on Thursday.

The 17-day campaign will determine whether the ruling coalition, currently a minority in the lower house, can retain a majority in the chamber by securing at least 50 of the 125 contested seats.

A total of 519 candidates have registered across electoral districts and proportional representation, including 152 women, nearly 30 percent of the total, marking the second-highest female representation on record, national broadcaster NHK reported.

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The central issue in the election is countering inflation, with parties proposing measures such as direct cash payments, reductions or abolition of the consumption tax, and interventions to address surging rice prices.

Additional debate is expected on pensions, social security, declining birthrates, and foreign policy, including responses to US tariff pressures.

Voting is scheduled for July 20.

The upper house has 248 members, and elections are held every three years to choose about half of the seats. The ruling coalition currently holds a total of 75 non-contested seats in the House of Councillors, which means they need to win 50 more seats in the current election to maintain a majority in the Upper House.

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Members serve a six-year term, and the election uses a mix of local districts and nationwide proportional representation.