Japan's prime minister has dissolved the powerful lower house of parliament and called national elections.

Prime Minister Taro Aso has set the vote for Aug. 30.

Japanese Prime Minister Taro Aso salutes to journalists upon arrival at his official residence in Tokyo Monday, July 13, 2009. The embattled prime minister has dissolved parliament and called a general election for next month. ((The Associated Press))

The speaker of the lower house announced the move Tuesday, setting the stage for a vote that could trigger a rare change in Japan's political leadership. The ruling Liberal Democratic Party has had a majority in the lower house for most of the past 50 years.

But the main opposition, the Democratic Party of Japan, has won a series of local elections and drawn broad support in recent polls.

Earlier this month, Aso's party and its coalition lost its majority in the Tokyo Metropolitan Assembly, prompting some to call for his resignation.

The municipal contest does not directly affect the national government, but it is widely viewed as a bellwether for a national vote.

The Democratic Party of Japan favours a more independent stance from the U.S., smaller government and more international peacekeeping missions for Japan's military.

The Liberal Democrats currently have 303 seats in the powerful 480-seat lower house, and their coalition partner Komeito has 31. The Democratic Party has just 112.

The party that wins a majority in the lower house picks the prime minister and government ministers from among its ranks.