Tokyo stocks could be in for a rough time next week if the ruling coalition loses its majority in Sunday's general election.

Any shortfall in the Liberal Democratic Party-Komeito seat total could shake confidence at a time when investors are already rattled by monetary-policy tightening and geopolitical concerns.

“If the ruling parties lose their majority, political uncertainty will significantly increase,” Masahiro Ichikawa, chief market strategist at Sumitomo Mitsui DS Asset Management, wrote in a report released Monday.