Voter turnout in Sunday's Upper House election fell short of the 50 percent threshold, topping out at 48.80 percent — the second lowest postwar total — the Internal Affairs and Communications Ministry said Monday.

The low turnout, despite a record number of early ballots for an Upper House poll, compared with 54.70 percent for the previous election for the chamber in 2016.

The lowest-ever turnout for an Upper House election was 44.52 percent in 1995, according to ministry data.

Voter turnout in the two pairs of western prefectures with small populations — Tottori and neighboring Shimane, and Tokushima and adjoining Kochi, were particularly low. Their respective constituencies were both united in a revised election law in 2015.

In Shimane, turnout fell sharply to 54.04 percent from 62.20 percent in the previous Upper House election.

Political analysts said this year's Upper House election failed to receive much attention due to a lack of clear-cut differences among parties stances on key issues. Torrential rain brought by a typhoon may have also affected voting in the country's southwest.