THE Governor, Mr Chris Patten, yesterday injected some flexibility into Sino-British negotiations over Hongkong's constitutional reforms by leaving open the timetable for putting his proposals to the Legislative Council. The prospect that Mr Patten would table before the legislative session ends in July the draft bills that give effect to his plans for the 1994/95 elections prompted China to warn against any attempt to pressure it into an agreement. In what is seen as a move to allow more room for the Sino-British negotiators to come up with a solution, Mr Patten said only that the administration aimed to allow legislators as much time as possible to discuss the 1994/95 bills. While this may placate Beijing, Mr Patten's remarks are certain to bring a sharp response from the pro-democracy side, which has already expressed fears that the Government's resolve might buckle and allow the July schedule to slide. Mr Patten was adamant that his credibility would not suffer if Beijing dragged out negotiations. Senior officials, including the Secretary for Constitutional Affairs, Mr Michael Sze Cho-cheung, had repeatedly indicated that they intended to enact the bill before the council went into recess on July 21. Mr Patten, who set out yesterday for a 10-day tour of the United States, said he had two aims in the current Sino-British talks. ''One is to give these talks a fair wind and to complete them successfully. ''The other, not unreasonably, is to give the Legislative Council as much time as possible to discuss the arrangements for 1994 and 1995 and to have arrangements in place well before those elections,'' he said. Asked if it was still possible to have the legislation enacted before the end of this session, Mr Patten said: ''You would, I think, find me less than sensible if I was to start ringing days in the calendar.'' Legislative Councillor Mr Yeung Sum is to ask the administration on Wednesday whether it will keep its promise to complete the legislative process by July. Mr Sze, who is a member of the British supporting team, is expected to reply. He returned to Hongkong with other British support team members yesterday and immediately went to the Government Secretariat to give a detailed report to the Deputy to the Governor, Sir David Ford. Another team member, the British Foreign Office's Hongkong Department head, Mr Peter Ricketts, will also give a full briefing to the Prime Minister, Mr John Major, when he returns to London. The teams will return to Beijing for a third round of talks between May 21 and 23. It is understood that both sides remained far apart on matters of principle. China yesterday hinted that Britain's failure to get back on track the ''three accords'' - the Joint Declaration, the Basic Law and previous Sino-British understandings - remained a major sticking point in the talks. A British source said the British team wanted to discuss specifics in the electoral package while the Chinese side insisted on focusing on matters of principle. The British side hoped Beijing could come up with its own proposals rather than quoting the Basic Law, which was vague on electoral arrangements. Although China insisted that Mr Patten's blueprint contravened the three accords, sources said Britain could not submit new proposals unless the Chinese side had made clear its position. The Chinese side could just keep turning down the proposals, the source said.