CHINA yesterday warned that Sino-British negotiations would come to an end if Governor Chris Patten tabled his electoral bill in the Legislative Council. A Beijing official said China would definitely not accept a move to table a bill which included a single-seat, single-vote system for the 1995 Legislative Council polls. Mr Patten is expected to announce today that he will table a partial bill covering voting age, voting method and the abolition of appointed seats. ''We can't help. How can we continue to talk to them if they have tabled the bill to Legco without an agreement?'' the official said. ''We have already stretched to our limit in making concessions. We have agreed to the abolition of the appointed seats. However, they insist on extending the single-vote, single-seat system to the Legco election.'' Yesterday, Mr Patten remained tight-lipped on the announcement he would make to Legco today. Stressing the lack of Sino-British agreement, Mr Patten said: ''We've had 17 rounds of talks. I think that is rather longer than many people would have been anticipating when we set out on this important venture. ''Seventeen rounds of talks and I am afraid that we haven't reached agreement on as many issues as the community would like.'' The Chinese official said it was unlikely that talks on the new airport projects would resume while the Sino-British row continued. ''We can hardly talk for the time being,'' he said. Under such circumstances, the Sino-British Joint Liaison Group's (JLG) next plenary session was unlikely to bear fruit, he said. It was unlikely that China would grant the land for the construction of Container Terminal No 9 in the next JLG meeting, to be held next Tuesday, because the British had failed to clarify all questions raised by the Chinese, he said. Besides, the Hong Kong Government had not finalised its deal on CT9 with the developer, he said. In Hong Kong, a leading member of China's working panel for the future Special Administrative Region (SAR) government, Leung Chun-ying, joined the opposition against the tabling of an electoral bill prior to a Sino-British accord. Mr Leung, the Hong Kong co-convenor of the political sub-group of the Preliminary Working Committee (PWC), warned that the act would only worsen the Sino-British negotiation and create an unfavourable atmosphere for the ongoing talks. There was a common feeling among the public that the tabling of the bill would not help the negotiation atmosphere between the two countries, he said. The political sub-group has decided to embark on the discussions on the formation of the first legislature for the SAR once the Hong Kong Government has tabled the electoral bill. Mr Leung said the group would assess the development of the situation in the PWC meeting in Beijing next week.