HONGKONG business leaders will tomorrow urge China to delay forming a working committee on post-1997 government. The influential Business and Professionals Federation (BPF) will urge the Chinese Government to postpone the setting up of a working committee as a precursor to the Preparatory Committee of the post-1997 government. Sources said the federation felt the establishment of the working committee in the present political atmosphere would affect local confidence and undermine the present government's authority. A 15-member delegation of the influential Business and Professionals Federation will visit Beijing tomorrow as the first round of the Sino-British talks on the territory's political reform gets underway. They are due to meet state leaders and the Director of the State Council's Hongkong and Macau Affairs Office, Mr Lu Ping. Led by BPF chairman Mr Vincent Lo Hong-sui, the delegation includes Mr David Gledhill, Mr Richard Li, Mr Peter Pun Chui-yin, Dr Samson Sun Ping-hsu and Dr David Wong. Others are legislative councillors Mr Henry Tang Ying-yeng and Mr Peter Wong Hong-yuen, and political heavyweights such as Sir David Akers-Jones, Sir Sze-yuen Chung, Mr James Tien Pei-chun, Mr Chan Wing-kee and Mr Hu Fa-kuang. Mr Tang said it would help achieve a smooth transfer of sovereignty if the working committee was formed with good will on both sides. He also said the federation did not have any concrete counter-proposals in mind, but they would advise the Chinese on broad issues regarding the 1994/95 electoral arrangements. On the so-called ''through train'', Mr Tang said they supported the concept that both the system and the candidates on board should be able to straddle 1997.