A group of lawyers filed lawsuits across the nation Monday seeking to nullify Sunday's House of Councilors election, arguing the unconstitutional disparity in the value of votes has gone uncorrected for too long.

It is the first time that the elections results for every district in the nation have been challenged. The suits were filed at all of the country's 14 high courts and branches.

Another group of lawyers meanwhile brought a separate case to the Hiroshima High Court seeking to invalidate the elections results for the Hiroshima prefectural district. The groups plan to file a similar suit in Tokyo.