TOKYO - Japan's main opposition party has kept its lead among voters over Prime Minister Taro Aso's long-ruling Liberal Democratic Party (LDP) before a looming general election, a newspaper poll showed on Monday.

A victory by the Democratic Party would end more than five decades of nearly unbroken rule by the business-friendly LDP and could break the political deadlock that has slowed policy-making in recession-hit Japan.

In the poll by the daily Yomiuri newspaper, 39.1 per cent of respondents said they would vote for the Democrats in proportional representation districts for the next election, down slightly from May, but still higher than support for the LDP.

Of the 1,057 voters surveyed, 28.7 per cent said they would vote for the LDP. The LDP is suffering from voter frustration over the recession and longer-term worries such as rising social security costs.

The general election must be held by October.

The Democrats, whose lead had narrowed earlier this year after a scandal involving a close aide to its leader, revived its election chances when the leader quit last month.

The party, along with smaller allies, has controlled the less powerful upper house of parliament since 2007.

Adding to Aso's woes, a poll by the daily Tokyo Shimbun showed 32.5 per cent of voters planned to cast their ballot for the Democrats in a closely watched election for the Tokyo assembly next month, more than the 20.3 per cent who would vote for the LDP. -Reuters