CHINA confirmed yesterday it would not support any amendments to Governor Chris Patten's reform proposals. Deputy Director of the State Council's Hong Kong and Macau Affairs Office, Wang Fengchao, said: ''It is entirely a matter for the political groups if they are going to amend the political package, no matter whether it is the 1992 or the 1993 model.'' Mr Wang's remark dealt a blow to Liberal Party legislator James Tien Pei-chun's call for legislators who are also Hong Kong affairs advisers to support the Liberal Party's and some independent legislators' move to water down the proposal. Mr Wang said the three-tier structure should be re-established by 1997 regardless of which model had been approved. by the legislature.