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.

Japan’s shaky ruling coalition is likely to lose its majority in the upper house, exit polls showed after Sunday’s election, potentially heralding political turmoil as a tariff deadline with the United States looms.

Exit polls suggest Prime Minister Shigeru Ishiba's coalition is likely to lose a majority its majority in the smaller of Japan’s two parliamentary houses in a key election.