The loss on Sunday left the Liberal Democrats a minority party in both houses of Parliament, while two new nationalist parties surged.

The fringe far-right Sanseito party emerged as one of the biggest winners in Japan's upper house election, gaining support with warnings of a "silent invasion" of immigrants, and pledges for tax cuts and welfare spending.

Its leader is a former supermarket manager who created his political party on YouTube in the depths of the coronavirus pandemic and campaigned on the Trumpian message “Japanese First.”