(excerpts from AFP report)

President Hu Jintao opened China's biggest political event in five years on Monday with pledges to curb the excesses of breakneck economic growth and implement political reforms.

Addressing the Party congress in Beijing, Hu said China's modernization drive since the late 1970s had created enormous wealth but at some environmental and social costs.

"Development patterns will be significantly transformed," Hu told 2,200 delegates at the Great Hall of the People in a nationally televised address.

Although he stressed fast economic growth was still a top priority, he said authorities had to take into account the "excessively high cost" on resources and the environment.

"There remains an imbalance in development between urban and rural areas, among regions and between the economy and society," Hu added, referring to the wealth divide across the country.

Hu also signaled gradual political reforms. "As an important part of the overall reform, political restructuring must be constantly deepened," he said, advocating more intra-Party democracy moves.

Hu also warned the delegates that corruption remained a threat to the survival of the Party. "Resolutely punishing and effectively preventing corruption bears on the popular support for the Party and on its very survival and is therefore a major political task the party must attend to at all times," he said.

On Taiwan question, the top leader called for a peace agreement with the island and used generally moderate language, though he insisted "Taiwan independence" would never be tolerated by 1.3 billion Chinese people.