The Dec. 16 Lower House election was conducted using the same electoral district boundaries used in the 2009 election that was ruled in a state of unconstitutionality by the Supreme Court. For that reason, the difference in the value of a vote between the most and least populous districts had increased to 2.43 times.
The Tokyo Election Administration Commission, the defendant in the case, argued that the call to invalidate the recent election should be rejected because time was needed to reapportion districts, and the 21 months between the Supreme Court ruling and the December Lower House election was insufficient to make that change.
Under the Public Offices Election Law, lawsuits seeking to invalidate election results are first submitted to high courts rather than district courts as is the usual case with lawsuits. While there is also a provision in that law that calls for efforts to be made to issue rulings within 100 days of the lawsuit being filed, that has previously not been followed to the letter. However, that has apparently changed, as the Tokyo High Court ruling came 79 days after the lawsuit was filed.