TRAVEL and entertainment by government cadres on unofficial business cost China's dwindling state coffers a staggering 100 billion yuan (HK$134 billion) last year, according to a mainland report. The statistic was revealed by the semi-official Hong Kong China News Agency yesterday as it called for official corruption to be halted before it eroded the authority of the communist leadership. In a special commentary on the state's No 1 enemy, the news agency lamented the fact that corruption was rampant despite a spate of party-led anti-graft campaigns. In addition to the huge bills incurred for meals and travel on non-government business by cadres, the report said ''some departments and individuals'' had ignored directives banning cadres from doing business, trading shares and accepting bribes. It said: ''Over the past 40 years, particularly since 1978, documents and speeches on anti-corruption and clean government have been repeatedly issued by the party central. ''Yet the decadent phenomenon of corruption and bribery facing us has become most serious than at any other time. The number of major cases is soaring, as is the number of party and government officials involved in economic crimes,'' the report said. It noted that more than 1,900 party and government cadres have been found to be involved in corruption this year. The number of corruption cases involving more than one million yuan has reached more than 100 since January, double the figure for the same period last year. ''The Communist Party will collapse without even a blow,'' the article warned. In order to eliminate the problem fundamentally, it said the legal system must be improved. A supervisory panel against official wrongdoings should be set up independent of the central Government in order to win public trust, it suggested.