TOKYO, JAPAN - Japan's opposition Democratic Party has won a closely-watched mayoral election, which is likely to bolster expectations of a victory over Prime Minister Taro Aso's ruling bloc in a looming national contest.

The opposition win in Sunday's local election comes as Aso faces fresh criticism for lack of leadership after his internal affairs minister, a close ally, quit on Friday following a weeks-long row.

Kunio Hatoyama was the third minister to resign since the 68-year-old Aso took office last September.

Democratic Party-backed candidate Toshihito Kumagai, 31, defeated ruling rival Kojiro Hayashi, 63 who was supported by the ruling Liberal Democratic Party (LDP), to become mayor of the city of Chiba near Tokyo.

It was the second local election victory for the Democrats since they replaced their scandal-tainted leader last month.

Public opinion polls have shown the Democrats well ahead of the LDP in the run-up to a general election that must be held by October and that many expect to be held in August.

A June 12-14 survey by broadcaster NTV showed support for Aso's cabinet fell more than nine points to 23.5 percent from the previous month, with more than 55 percent opposed to the prime minister's decision to have Hatoyama step down.

The poll showed 38.9 percent planned to vote for the Democrats in the general election versus 26.3 percent for the LDP.

A Democratic Party victory in the general election would end more than five decades of almost unbroken rule by the
conservative LDP and bring to power a party pledged to pay more heed to the interests of consumers and workers than corporations.

The Democrats have also vowed to pry control of policy-making from bureaucrats as a way to cut waste and shift spending priorities, and to adopt a diplomatic stance more independent of close security ally the United States. --REUTER