The establishment of Tokyo Governor Yuriko Koike’s Party of Hope — which scalped candidates from the centre-right factions of the DP — failed to challenge the LDP. As a result, this election was conducted without a large opposition party capable of replacing the LDP and providing an alternative political orientation.

So where to now for Japan’s party system? The answer at this stage is not clear, but Japan’s attempt to create a two-party system following the 1993 electoral reform faces a critical juncture.

Before the 1990s, post-war Japanese politics was characterised by a lack of changes in government, with the political system dominated by the LDP. The LDP, as a catch-all party, occupied the absolute majority of the Diet. The second largest party in the system, the Japan Socialist Party, usually occupied about half as many seats as the LDP. But it never truly challenged the LDP for power because it refused to make practical ideological concessions. Neither a coalition or change in government between the two parties was possible.

Political reform became a hot policy issue from the late 1980s in the face of continuing corruption and money scandals surrounding LDP factional politics. It was widely hoped that the political system could be changed to enable smooth changes of government. At the core of this idea lay electoral reform.

A system of single-member electoral districts in parallel with regional proportional representation blocs was introduced by the Hosokawa government in 1994 for the lower house. It was hoped this would incentivise the formation of a two-party system. In 2009, this electoral reform saw the Democratic Party of Japan (DPJ) win government. The two-party system was expected to provide a healthy democracy for Japan.

But the DPJ’s three years in power ended in disaster with the party losing public confidence and the LDP was returned to power. Since then public support for the DP, the DPJ’s successor party, continuously polled below 10 per cent, while the LDP’s approval ratings averaged at least 30 per cent.

The DP failed to change its poor image. Old leaders who were discredited during its time in office continued to occupy key positions, disregarding the public’s dissatisfaction with the lack of party reform.

After the most recent election was called, the new DP leader Seiji Maehara desperately initiated a migration of its candidates to the Party of Hope with the intention of establishing an opposition capable of winning government from the LDP. But its public support soon dissipated after Koike excluded politicians from the DP’s centre-left factions who would not uphold her conservative stance on constitutional reform and the security-related bills. This move gave the impression that Hope was a spin-off rather than an alternative to the LDP.

At the same time, a number of the excluded DP politicians formed their own new party, the Constitutional Democratic Party of Japan (CDPJ) led by Yukio Edano.

The prospects for establishing a two-party system now appear dim. There are fundamental problems in the way Japan’s two-party system has been created.

First, Japanese policymakers have sought to change the party system primarily through electoral reform. The two-party system was modelled after the Westminster system, but this reflected neither the accumulation of practice in Japanese politics nor the social and economic cleavages of society.

The DPJ was created by ideologically disparate political groups to challenge the LDP under the new electoral system. But its organisational structure was weak compared to the LDP. It relied heavily upon Rengo — a collective body of different labour unions — for electoral support, but beyond this its base of core supporters was weak.

Second, elections in Japan have been largely contingent upon the public mood towards the LDP rather than choices for different policy orientations. In recent elections, independent voters — which make up about 30–50 per cent of Japan’s electorate — have played the key role. They chose the DPJ in 2009 due to considerable anti-LDP sentiment.

A number of new political parties which were born through criticism of the LDP have come and gone. These parties received enthusiastic support from the public during times of anti-LDP sentiment. But such transient support never developed into an opposition party with core supporters. The Party of Hope was born in such a context.

Third, policy debate between the ruling parties and the opposition parties rarely occurs on an equal footing. Rather, the LDP–Komeito coalition generally makes one-way explanations in response to opposition criticism.

The majority of the public are not necessarily satisfied with Japanese politics today. The LDP won, but public opinion is more cautious toward the LDP than the election outcome indicates. The rise of the DPJ in the 2000s reflected public expectation of a two-party system, but this expectation was dashed after its three years in power ended in failure.

The road ahead to establish a two-party system in Japan looks difficult. But if Japan believes that this is the way to better its democracy, policymakers should listen to public dissatisfaction and reform should again be sought to create a competitive party system.

Toshiya Takahashi is associate professor at Shoin University, Japan.