A survey by the conservative Yomiuri newspaper published on Wednesday concluded that opposition parties were rapidly making up ground on the LDP and its coalition partner Komeito, with seats that were previously considered safe now very much in the balance.
A public-opinion poll published the previous day by the left-leaning Asahi echoed that position, suggesting that of the 125 seats in the 248-seat chamber being contested, the LDP was on course to win only 34 while Komeito would take about nine.
Combined with the 75 seats not up for re-election, that will give the coalition 118 spots, below the 125 required for a majority.
That would be a crippling blow to the LDP given that it lost its majority in the House of Representatives in October last year, leaving Ishiba heading a fragile minority government.
Michael Cucek, a professor of politics and international relations at the Tokyo campus of Temple University, said the collapse of political parties often mirrored the fall of currencies.
