Opposition parties are ratcheting up criticism of Prime Minister Shinzo Abe's reported drive to reduce the amount of time they are given to grill him and his Cabinet ministers in Diet debates, equating such a move to an attempt to avoid being held accountable amid a series of scandals.

Soon after his ruling coalition won by a landslide in the snap election earlier this month, Abe reportedly instructed high-ranking officials in his Liberal Democratic Party to rethink the large amount of question time currently allocated to the opposition.

Six opposition parties, including the Constitutional Democratic Party, Kibo no To (Party of Hope) and the Japanese Communist Party, agreed that the LDP's bid to limit their chance to question the government is "unacceptable" and that the traditional ratio should be maintained.