FACTBOX-Key facts about Democratic Party of Japan

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July 13 (Reuters) - Japanese Prime Minister Taro Aso plans to call a general election on Aug. 30, a top ruling party official said on Monday, despite the prospect that his long-ruling conservative party is headed for a big defeat. [IDn:T353403]

The main opposition Democratic Party has its best ever chance of ousting Aso's ruling Liberal Democratic Party and its junior coalition partner in the poll, ending a half-century of nearly unbroken rule by the conservative LDP.

Below are some key facts about the Democrats and its leader, Yukio Hatoyama:

*The DPJ was created through a merger of several smaller opposition parties in 1998 and expanded further in 2003 by joining with the small Liberal Party. The party had extended its presence in parliament's lower house until suffering a big setback in a 2005 poll called by then-prime minister Junichiro Koizumi as a referendum on his plan to privatise the postal system. The party now has 112 members in the lower house.

*The current party leader is Yukio Hatoyama, 62, a Stanford University PhD who was a founding member of party. He previously served as party leader from 1999-2002.

*Hatoyama took over as party leader in May after his predecessor stepped down to keep a fundraising scandal from hurting the party's chances at the polls. Hatoyama's fundraising has also come under scrutiny but he has denied illegality. He apologised that some people listed as political donors were dead.

*The DPJ is an amalgam of former LDP members, socialists and younger conservatives, making it difficult at times for the party to agree on security and other policies. Hatoyama has called for cutting wasteful expenditure by wresting spending power from bureaucrats and rebuilding faith in the creaking national pension scheme.

*The party's policy proposals include financing minimum pension allowances with tax revenues while avoiding a rise in the 5 percent consumption tax for another four years, aid for farmers and ending a special surcharge on gasoline.

*Spending on policies will come in stages. The party plans monthly child-rearing allowances of 26,000 yen ($281) per child although initial payouts would be half that amount.

*Annual spending will reach 16.8 trillion yen in the fiscal year from April 2013 when all key policies are implemented, a newspaper reported last week. Some analysts have doubts over the party's ability to fund spending but it plans to cut wasteful spending and tap the surplus in special government accounts. ($1=92.46 Yen) (Reporting by Linda Sieg, Chisa Fujioka)