Campaigning for the Sept. 11 House of Representatives election officially kicked off Tuesday with 1,132 candidates throwing their hats in the ring for 480 seats.

The race to fill 300 single-seat districts and 180 proportional representation seats is being widely portrayed as a plebiscite on Prime Minister Junichiro Koizumi's leadership and his plan to privatize the postal service.

Koizumi promised a crowd outside JR Kichijoji Station in western Tokyo that his Liberal Democratic Party would push ahead with his reform agenda and transform the face of politics.