Tokyo ? It sounds like mission impossible: Take the developed world’s longest-ruling political party, one weighed down by a history of corruption, waste and patronage, and turn it into a symbol of change.

Japanese voters will decide whether Prime Minister Junichiro Koizumi has accomplished that task for his Liberal Democratic Party during today’s elections for the 480 seats in the lower house of Parliament.

The balloting caps a dramatic campaign that has broken new ground in postwar Japanese history, heralding the emergence of media-driven image politics and a sharper focus on policy, in this case Koizumi’s quest to privatize the cash-rich postal service as part of economic reforms.

Media polls suggested that was what voters would do, pointing to a strong showing by the LDP. Some surveys indicated the party, which has ruled for almost all of the past 50 years, would strengthen its majority.

Koizumi’s main rival, Katsuya Okada, leader of the Democratic Party of Japan, argued that the country has more pressing concerns than the postal service, such as the strained pension system and burgeoning government debt.