The Liberal Democratic Party officially kicked off its presidential election campaign Wednesday with five candidates angling to succeed Prime Minister Yasuo Fukuda, who announced his resignation last week.

Whoever wins the Sept. 22 LDP poll will face increasing pressure, however, to dissolve the Diet and call a general election, possibly in November.

The five candidates — LDP Secretary General Taro Aso, economy and fiscal policy minister Kaoru Yosano, former Defense Minister Shigeru Ishiba, another ex-defense minister, Yuriko Koike, and former LDP policy chief Nobuteru Ishihara — held a joint news conference Wednesday afternoon to announce their platforms.