A bad night for the ruling coalition could cost the prime minister his job and make it harder to strike a deal with Washington before the August tariff deadline.

Japan is facing trade and political uncertainty after a historic defeat for the prime minister’s ruling party. Shigeru Ishiba is trying to buy time for his premiership following this past weekend’s election, which left the ruling bloc three seats short of a majority in the upper house.

If the current ruling party loses its majority, the country’s waters could become uncharted at a critical time.