ZHANG Baifa, the charismatic deputy mayor of Beijing, has a tendency to shoot from the hip. Unfortunately, when he took aim at the United States Congress on Friday for its opposition to his city's bid to host the 2000 Olympics, he only succeeded in shooting himself in the foot. Mr Zhang's threat to boycott the 1996 Games in Atlanta should Beijing's bid be thwarted by political pressure from the US, has caused consternation in international sporting circles and dismay in his home town. ''What a cretin! How could he say that,'' fumed a Beijing businessman who hopes to cash in on the economic opportunities which would accrue from winning the bid. ''He's really stuffed it up this time.'' The deputy mayor's colleagues at the bid committee's headquarters were none to happy either, immediately putting out a statement there was no question of a boycott. But the real anger in government circles, insiders said, was not because Mr Zhang had got it wrong (again) but because he had leaked what amounted to a state secret. There is a contingency plan, sources say, to boycott Atlanta but only as a last resort and on no account was that contingency to be made public, certainly not one week before the crucial International Olympic Commission vote in Monte Carlo. ''The government has been discussing a whole range of possible response measures to not winning the 2000 Games and not going to Atlanta has been mentioned,'' a source close to the bid committee said yesterday. ''But it is very much an emergency measure and it certainly does not have overall support within the committee.'' It was only the hardline Communist Party stalwarts on the committee who had suggested such drastic retaliatory measures. The more moderate members of the committee, such as the president of Chinese Olympic Commission, He Zhenliang, are firmly opposed tosuch a move. Even the slightest hint of a boycott, the moderates reportedly argued, would damage China's chances. Mr He may claim that as commission president it is his decision whether to attend the Atlanta Games but everyone in Beijing knows the final decision will be made at the highest levels of the Communist Party. ''This is a high-level political matter. He Zhenliang doesn't really have much say,'' a source said. But the question remains why did Mr Zhang threaten a boycott during his interview with an Australian television station. The simplest answer is - and not for the first time - he lost his temper. Mr Zhang has a reputation for speaking his mind, and when goaded by a foreign reporter on China's human rights record and the demands of the US Congress, it is not surprising he would blurt out something less than diplomatic. A poorly educated former construction worker, who in the 1950s served as the head of one of the party's youth shock brigades, Mr Zhang does not have the diplomatic skills to front an international campaign to sell China to the world. He could not even get his speech at the opening ceremony of the seventh National Games in Beijing correct. His handlers should simply have refused the interview request and told Australia's SBS television to talk to Mr He. Should Beijing lose out on Thursday, there will inevitably be calls for Mr Zhang's head. The deputy mayor who once promised to jump off the top of Beijing's tallest building if the 1990 Asian Games were not a success, may just have to make good that promise.