THE Beijing 2000 telephone hotlines have been jammed over the past week. Since Hong Kong Telecom announced that Andy Lau and Leon Lai had recorded messages in Mandarin and Cantonese thanking callers for showing their support for the Beijing bid, fans have been racing to their phones to listen to the voices of their pop star heroes. ''It was quite unexpected . . . so many calls,'' a Telecom engineer said. He confirmed that the system had broken down altogether on Wednesday afternoon because of excessive demand, but after the engineers had managed to get the lines working again, 8,505 votes were recorded. Lau's recorded message led Lai by a margin, scoring 4,543 calls, compared with Lai's 3,068 callers. Since the hotlines opened on September 3, there have been at least 45,000 calls from Hong Kong and overseas. The numbers to call for Lai's message are 187 8826 and 187 8827, while Lau can be heard on 187 8828 and 187 8829. There is also an English-language hotline on 187 8830, and a message for international callers on (852)17278208. All tapes include a voice track recorded over the Beijing 2000 theme tune. The lines will be open, system capacity permitting, 24 hours a day until 2 am on September 24 when the IOC vote is expected. Organisers say a tally will be taken on September 23, and the IOC will be informed of the number of telephone votes of support there have been. Signatures on a pro-Beijing 2000 petition are still being collected at all branches of the Bank of China. More than 50,000 signatures have been collected so far, according to a running tally held by the Federation of Trade Unions, which has organised the event. ''We are expecting something in the region of 100,000 signatures by next week,'' claimed Beijing 2000 Support Group organiser, Alexander Wan.