TOKYO (Reuters) - Japan's opposition Democratic Party lashed out Friday at what it charged was a misleading negative campaign by the ruling party ahead of an election that Prime Minister Taro Aso's coalition is in danger of losing.

Analysts say Aso's Liberal Democratic Party (LDP), shaken by internal feuds and facing a possible loss in an August 30 poll, is making attacks on the Democrats of a sort rare in a country where many have had an allergy to Western-style negative campaigns.

Struggling to avert an election loss that would mark the end of a half-century of almost unbroken rule, the LDP has made clear its strategy of attacking the Democrats as weak on security policy and irresponsible on public finances.

Wednesday, the LDP ran a full-page advertisement in the conservative Sankei newspaper, with a big, bold-faced headline declaring: "The Future of Japan is in Danger."

Democratic Party Secretary-General Katsuya Okada blasted the ad, as well as recent televised remarks by his LDP counterpart, as containing misleading statements about his party's policies.

"It is natural for there to be healthy criticism and debate about policies, but the stance of the LDP, which is stressing partial, biased information and is not engaging in serious debate, is extremely regrettable and sad," Okada told a news conference.

An opposition Democratic Party victory would usher in a government pledging to pay more heed to consumers than companies, wrest control of policy from bureaucrats to reduce waste, and adopt a diplomatic stance less subservient to ally the United States.

It would also raise the chances of ending a political deadlock resulting from a divided parliament in which the opposition controls the upper house, which has delayed policy implementation as Japan struggles to emerge from a deep recession.