Japan's ruling coalition likely to lose upper house majority, exit poll shows

Japan's ruling coalition is likely to lose its majority in the upper house, an exit poll for Sunday's election showed, potentially fuelling political instability in the world's fourth largest economy as a tariff deadline with the United States looms.

While the ballot does not directly determine whether Prime Minister Shigeru Ishiba's shaky minority government falls, it heaps pressure on the embattled leader who also lost control of the more-powerful lower house in October.

Ishiba's Liberal Democratic Party (LDP) and coalition partner Komeito needed 50 seats to retain control of the 248-seat upper chamber in an election where half the seats are up for grabs. They are forecast to secure 32 to 51 seats, the exit poll by public broadcaster NHK showed.

The LDP, which has ruled Japan for most of the post-war period, had its worst showing in 15 years in October's lower house election.

That has left Ishiba vulnerable to no-confidence motions that could topple his administration and trigger a fresh general election.