BEIJING - Hu Jintao on Thursday said the Communist Party of China (CPC) must make unremitting efforts to combat corruption, promote integrity and stay vigilant against degeneration.

Hu said combating corruption and promoting political integrity, which is a major political issue of great concern to the people, is a clear-cut and long-term political commitment of the Party.

"If we fail to handle this issue well, it could prove fatal to the Party, and even cause the collapse of the Party and the fall of the state," Hu warned in a keynote report at the opening of the 18th CPC National Congress.

Hu said the CPC must maintain a tough position in cracking down on corruption at all times, conduct thorough investigations into major corruption cases and work hard to resolve problems of corruption that directly affect the people.

"All those who violate Party discipline and state laws, whoever they are and whatever power or official positions they have, must be brought to justice without mercy," he said.

Hu also emphasized centralized leadership of the CPC, saying that no one is allowed to place oneself above the Party organization.

Centralized leadership of the Party is the source of its strength and a fundamental guarantee for China' s economic and social development, ethnic unity and progress, and enduring peace and stability, Hu said.

Party organizations at all levels and all Party members and officials, particularly principal leading officials, must willingly abide by the Party Constitution as well as its organizational principles and guiding principles for its political activities.

All Party organizations and members must resolutely uphold the authority of the Central Committee and maintain a high degree of unity with it theoretically, politically and in action, Hu said.