CHINA has stepped up work on the body which will prepare for the setting up of the Special Administrative Region (SAR) Preparatory Committee. Meanwhile, Hongkong deputies to the National People's Congress (NPC) yesterday decided to demand a seat at the NPC Standing Committee meeting in Beijing this month, which will discuss arrangements for the establishment of the body, known as a working organ. The SAR Preparatory Committee will set up the SAR's first government and legislature. Chinese sources said Beijing had increased preparation and consultation for the working organ because the British side had shown ''limited sincerity'' in the Sino-British talks by playing ''too many little tricks''. They said Beijing would decide whether to set up the working organ before the end of the month, after the fifth round of Sino-British talks, to be held in Beijing from next Monday to Wednesday. The One Country - Two Systems Economic Research Institute, a pro-Beijing think-tank, yesterday organised a closed-door seminar to discuss the working organ. Leaders of nine political groups discussed the composition, organisational framework, function, responsibilities and timing for its establishment. Participants included Frederick Fung Kin-kee, legislator and chairman of the Association for Democracy and People's Livelihood, and Tsang Yok-sing, chairman of the pro-China Democratic Alliance for the Betterment of Hongkong. Speaking after the seminar, Shiu Sin-por, executive director of the research institute and a Hongkong affairs adviser, said the participants agreed that China should start preparing for the setting up of the SAR government. ''The participants have expressed their opinions on the responsibilities and organisation of the working organ. We will compile their opinions and deliver them to both the Chinese Government and the Hongkong Government,'' Mr Shiu said. ''Since the NPC Standing Committee is going to meet later this month, it is necessary for some people to do the preparation work.'' The local NPC deputies urged the Chinese Government to widen consultation among Hongkong people on the responsibilities and composition of the working organ. Initiating the motion, Cheng Yiu-tong, NPC deputy and a Hongkong affairs adviser, said allowing local deputies to attend the Standing Committee meeting would mean public opinion in Hongkong could be reflected.