Campaigning for the Sept. 11 Lower House general election effectively got under way Tuesday, one day after Prime Minister Junichiro Koizumi dissolved the chamber on the heels of the House of Councilors' rejection of his postal privatization bills.

Koizumi repeated that he will step down as prime minister if his Liberal Democratic Party and coalition ally New Komeito fail to win a combined majority in the Lower House.

"This is an election to ask voters whether they support or oppose postal privatization, and I believe a number of people will say yes" to privatization, Koizumi told reporters in Nagasaki, where he attended a ceremony to mark the 60th anniversary of the 1945 atomic bombing.