In what is believed to be their last joint news conference before next week's LDP presidential election, the four candidates on Wednesday debated topics ranging from economic policy to social welfare at the Japan National Press Club in Tokyo.

Their remarks basically followed the platforms they have already unveiled.

Although votes that local LDP members have begun to mail to local chapters are expected to play a big role, some of the candidates tried to play down the preliminary balloting.

Taro Aso, state minister in charge of economic and fiscal policy, said LDP Diet members will not necessarily be affected by the outcome of the preliminary. He called it "natural" for lawmakers, who have daily contact with the candidates, to have different impressions.

Former Prime Minister Ryutaro Hashimoto agreed with Aso, saying the result of the presidential election on Tuesday will be determined by both local LDP members and Diet members.

LDP policy chief Shizuka Kamei stressed that the candidate's policy and trustworthiness will be important elements in considering who to vote for should a runoff take place.

A runoff will be held if no candidate wins 50 percent of the votes.

Meanwhile, when asked whether he would bow out should he not secure the local votes, former health minister Junichiro Koizumi said the fact that the question was even posed proves he has a fair chance of winning.

"When I ran for the presidency six years ago against Mr. Hashimoto, nobody asked me such a question because everybody knew he would win," Koizumi said.