TOKYO - JAPAN'S opposition party is ahead in voter polls to win a key local election on Sunday, media polls showed on Monday, boosting the possibility that moves will grow to oust Prime Minister Taro Aso before a tough national vote.

The July 12 election for the Tokyo Metropolitan Assembly is being seen as a gauge for a general election due by October that Mr Aso's ruling coalition is in danger of losing.

A loss by the Liberal Democratic Party (LDP) in the national election, which many expect in August, would mark the end of more that five decades of nearly unbroken rule by the business-friendly party.

In a poll by the Yomiuri newspaper, 29.4 per cent of respondents said they would vote for the main opposition Democratic Party in the Tokyo election, while 22 per cent said they would opt for the LDP or its junior coalition partner. Other media polls also showed the Democrats with a solid lead.

An opposition-backed candidate won an election for governor in central Japan on Sunday, adding to speculation that lawmakers within the LDP would seek to replace the unpopular Mr Aso while trying to delay the national vote. -- REUTERS