Elections for half the membership of the House of Councillors, the upper house of the Japanese parliament (Diet) are due in July or August. The precise date has not yet been set.
Role of the upper house
Japan is a parliamentary democracy with two houses of parliament. The lower house of the Diet, the House of Representatives is the chamber responsible for sustaining a government in power. Legislation passes through both houses of the Diet and in the normal pattern of events a consensus is formed between the wishes of both chambers.
Term of office
House of Councillors elections are held for half the membership of the house at a time, and take place every three years (the term of office is therefore six years). There are 242 seats in total and therefore 121 members elected at a time. The previous election was for the other half-membership and took place in July 2016, and these seats were last fought in
There is speculation that a double election might be called, i.e. that the Prime Minister Shinzo Abe might choose to dissolve the House of Representatives and that there would be an election for the lower house as well as half the upper house.
The electoral system is Mixed, in that it has both proportional and non-proportional elements. Following electoral reforms passed in August 2018 there have been some modest changes to the system, including re-allocation of geographical constituencies to partially reflect movements of population and an increase in the number of proportional representation seats. Last time these seats were fought (in 2013) there were 73 members elected by simple plurality (First Past the Post) in geographical constituencies – 32 single-member seats and 13 seats which elect between two and six members at a time. There is also a minimum share of the vote required to be elected to these seats. The other 48 seats were elected in a single nationwide electoral district and allocated proportionally between the parties’ votes. Six additional seats are being added this time, four proportional and two for geographical seats.
The parties of the ruling coalition (the Liberal Democratic Party and Komeito) did well in the 2013 House of Councillors elections and gained a majority in the upper house. They made further gains in 2016 but did not reach as high a point as they did in 2013, so even if the government is fairly popular they might still lose some seats.
Sources and further reading
Website of the Japanese House of Councillors (English language version)
Inter-Parliamentary Union (IPU) data archive on House of Councillors election
‘Japan’s Upper House Electoral Reform Sparks Democracy Debate’ Thisanka Sirapala, The Diplomat 8 August 2018