Yukio Hatoyama, leader of the Democratic Party of Japan, underlined Saturday his newfound resolve to challenge Prime Minister Junichiro Koizumi's structural reform drive.

Hatoyama told a party convention that the prime minister has failed to steer Japan out of the economic downturn in the eight months since he took office, in a reversal from Hatoyama's former position of broadly supporting Koizumi's reforms.

"Now I find Mr. Koizumi's reform measures are 'cold' ones," Hatoyama said to some 300 people attending the conference at a Tokyo hotel, criticizing the prime minister's policies and remarks over the structural reforms for lacking proper attention to the public.

"Formerly, I tried to trust in Mr. Koizumi because his reform schemes had seemed similar to the ones we drafted. But all the economic data has since got worse," he said.

Hatoyama also indicated his intention to form an opposition alliance to fight the ruling coalition led by Koizumi's Liberal Democratic Party.

"In particular, the opposition alliance will confront the government on its sloppy management of the outbreak of bovine spongiform encephalopathy," he said.

He was referring to the discoveries of cows infected with mad cow disease since last September and the subsequent erroneous disclosure of information by the government to curb fears of food safety.

In connection with the mad cow disease row, Hatoyama said the DPJ will invite other opposition parties to submit a no-confidence motion against Tsutomu Takebe, minister of agriculture, forestry and fisheries, during the upcoming Diet session that is to convene Monday.

DPJ members confirmed their policy of requesting that Koizumi's reform schemes focus on such areas as environmental conservation, education and welfare.

Participants adopted an action plan for 2002 featuring a revision of the party's rules, including increasing grants to local chapters that increase the number of new party members at each local office.