Despite the Liberal Democratic Party's resounding victory in Sunday's Tokyo Metropolitan Assembly election, experts said it remains unclear whether the groundswell will mean very much in the Upper House election next month.

While the Tokyo poll apparently showed that Prime Minister Junichiro Koizumi — also the LDP chief — has succeeded in capturing the hearts of urban voters, his reform-oriented policies may backfire in rural constituencies, the party's traditional strongholds.

In Sunday's election, 53 of the 55 candidates fielded by the LDP won, pushing up the party's strength in the assembly by five from 48 before the poll.