TOKYO: Japan's opposition Democratic Party may be headed for a landslide election victory, trouncing the conservative party that has ruled for most of the past half-century, a leading newspaper said yesterday.

The Democrats could win 300 of the 480 seats in parliament's lower house while the long-ruling Liberal Democratic Party (LDP) may see their strength halved to around 150 seats, said the Asahi newspaper, based on a detailed survey of electoral districts ahead of the August 30 poll.

But the paper also said around 30 to 40 percent of voters in its survey of electoral districts had not revealed how they would vote while 25 percent might change their minds, so results could shift significantly in the final days.