Legislative Council by Governor Sir David Trench in April 1965, as well as member of the Trade and Industry Advisory Board, Hong Kong Telephone Advisory Committee, Hong Kong Aviation Advisory Board, Hong Kong Government Radiation Board, Working Committee on Productivity and a Justice of the Peace. In 1968, Chung became the permanent member of the Legislative Council and was appointed to the Executive Council by Governor Sir Murray MacLehose in 1972. In 1974 Chung became the Senior Member of the Legislative Council. In order to explore the Hong Kong's prospects after the expiry of the New Territories Land Lease in 1997, an Advisory Committee headed by Financial Secretary Sir Philip Haddon-Cave was set up in 1977 in which Chung was also a member. In 1980, the Advisory Committee submitted a four-page letter to the Governor to ask for the government to begin preliminary negotiations on the subject of sovereignty. Executive Council Senior Member In 1978, Chung resigned from the Legislative Council to devote more time in the Executive Council. He was also appointed a Knight Bachelor in 1978. After Senior Member of the Executive Council Sir Yuet-keung Kan and Sir Sidney Gordon both retired in August 1980, Sir S.Y. Chung became the Senior Member, the highest representative position in the government and the "leader of the Hong Kong community". Question of Hong Kong prospects During his service as the Senior Member of the Executive Council, he witnessed the negotiations of the British and Chinese governments over the sovereignty of Hong Kong. Before the beginning of the negotiations, he was invited to sit in the Chinese People's Political Consultative Conference (CPPCC) in which he declined the offer as he saw it would be a betrayal to the British government. In September 1982, the Unofficial Members of the Executive and Legislative Councils (UMELCO) headed by Chung sent a five-member delegation to London with Roger Lobo, Li Fook-wo, Lydia Dunn and Chan Kam-chuen to meet with Prime Minister Margaret Thatcher over the 1997 issue to suggest the status quo of British administration in Hong Kong. He met with Thatcher and urged the British government to trust the Executive Council after The Observer revealed the Beijing position on Hong Kong in which the Executive Council was not notified after her Beijing visit in December 1982. However, the "three-legged stool" proposal of the Hong Kong representatives besides the British and Chinese sides on the negotiation