SINO-BRITISH talks over Hongkong's future political reforms ended yesterday with China warning Britain against being pressured into an early agreement. With no progress reported following a second round of talks, both sides announced a three-week adjournment until May 21. The break, forced by the absence of Chinese team leader Mr Jiang Enzhu, who leaves for an official visit to Europe on Sunday, tightens the schedule for tabling draft legislation in the Legislative Council which would still allow time for arrangements to be introduced for the 1994/95 elections. Some legislators were concerned that China was using stalling tactics to delay enactment of the bill. However, a locally-based Chinese official denied that, saying it was unrealistic to expect the two sides to settle such complicated issues through two or three rounds of talks. Instead, he criticised the British side for trying to pressure Beijing by imposing a timetable for an agreement. ''There is no need to rush into an early agreement. If the British really show sincerity in holding the talks, they should allow the talks to take time so that a satisfactory settlement can be carefully worked out,'' he said. The official urged the British side to be prepared for protracted talks because the electoral arrangements for 1994/95 involved complicated and difficult issues. Lack of progress so far was indicated by a tersely-worded joint statement that said only that the third round would be held from May 21 to 23 in Beijing in accordance with the Sino-British Joint Declaration, the principle of convergence with the Basic Law and previous agreements reached between the two sides. Despite two days of discussions, sources said both sides remained far apart on matters of principle, with China failing to present any concrete proposals for the 1994/95 elections. It is understood the main sticking point in the latest round was whether the proposals of the Governor, Mr Chris Patten, were in line with the three accords. When asked why the next round would be held a week after Chinese negotiator Mr Jiang returns from his overseas trip, British negotiator, Sir Robin McLaren, would only say that it was the earliest date given by the Chinese side. Chinese sources insisted their side would not ''stall for time'' and insisted it was still premature for China to say who would continue serving for Legco after 1997. Chinese sources also said it was difficult for the talks to proceed to discussions on concrete matters of the electoral arrangements as the two sides had failed to reach a consensus on basic principles. ''The British side still claimed that the Patten package did not violate the three accords while China disagreed the vetting of legislators in 1997 was unfair and unacceptable to the people of Hongkong,'' a source said. It is understood that China was also irritated by an earlier pledge from the British side that liberal legislators Mr Martin Lee Chu-ming and Mr Szeto Wah would not be sacrificed in exchange for an agreement. Yesterday's talks were unexpectedly short with negotiators emerging after only two hours of discussions. Deputy director of the State Council's Hongkong and Macau Affairs Office Mr Chen Ziying yesterday compared the talks with climbing the Great Wall of China. ''If one wants to climb to the peak of the Great Wall, one has to strive hard,'' said Mr Chen before his meeting with a group of Hongkong workers' representatives. The British negotiating team will return to Hongkong today and give a full briefing to the Executive Council. Although Mr Patten will travel to the United States today, he is said to have been kept fully briefed over the progress of the talks. A British Embassy spokeswoman said Sir Robin, the British Ambassador to China, might come to Hongkong during the break. Legislators expressed concern over the three-week adjournment and the effect on the electoral reform bill timetable. United Democrats vice-chairman Mr Yeung Sum will seek to file a question in the Legislative Council next Wednesday, on whether the Government will keep its promise to complete the legislative process by July and to ask when the bill will be tabled for first and second reading. United Democrats Chairman Mr Lee was concerned that the Government's credibility could be undermined if it failed to live up to its promise of having the legislation passed before the end of this session. Independent legislator, Ms Emily Lau Wai-hing, said China might be trying to hold up passage of the bill. She suggested Legco might need to postpone its summer recess to discuss the package if the bilateral talks delayed the legislative procedures beyond July. But pro-China legislator Mr Tam Yiu-chung cautioned against making any suggestion about contingency plans or the tabling of the electoral bill before any agreement was reached. Given that more time was needed for both sides to hammer out an acceptable solution, Mr Tam as well as appointed legislator Miss Anna Wu Hung-yuk said legislators could vet the electoral bill during the summer recess. But they added that it would be preferable to have the bill tabled before the end of this legislative session to allow for completion of the process by December. Liberal Party preparatory committee member Mr Steven Poon Kwok-lim said it was a good sign that the two sides at least set a date for the third round, although it was a bit late. Mr Poon also said the Liberal Party believed if the final package could be submitted to the Legco after the summer, there was still enough time left for members to scrutinise it.