Sunday’s general election saw a crushing defeat for the effort by the main opposition Constitutional Democratic Party of Japan and Japanese Communist Party to field unified candidates in single-seat electoral districts, raising questions as to whether they should continue with such a strategy in future elections.

Despite the unprecedented move to get behind one candidate in as many electoral districts as possible in order to avoid splitting the opposition vote, the CDP finished with 96 seats, down from 110 before the election. The JCP won 10 seats, down from 12 before the election.

The worse-than-expected results shook CDP officials. The party's leader, Yukio Edano, apologized for the results Monday morning, saying he will decide his own fate by Tuesday. CDP Secretary-General Tetsuro Fukuyama said he would resign his post in order to take responsibility for the losses.