A SENIOR Chinese leader has told a leading Hong Kong businessman that Beijing will not make any concessions in the Sino-British talks on the 1994/95 electoral arrangements. Chinese Vice-Premier Li Lanqing was quoted by businessman and Hong Kong affairs adviser, Tsui Tsin-tong, as making the remarks at a meeting held on Tuesday, only three days before Sino-British negotiators gather for a crucial round of talks. The 16th round of constitutional talks begins tomorrow and Christopher Hum, head of the North Asia Department of the British Foreign Office appointed to sit in as British team leader while Sir Robin McLaren is on sick leave, arrives in Hong Kong today inpreparation for the talks. Sir Robin, the British ambassador to Beijing who served as the chief British negotiator in the last 15 round of talks, is suffering from a back problem and underwent surgery in London last week. Britain, following last week's Cabinet committee meeting, has proposed to the Chinese side that three simple issues - the lowering of the voting age from 21 to 18, the single-seat, single-vote election method and the abolition of appointed district boardseats - be tackled before controversial subjects such as the through-train. British officials are understood to be hoping China will offer quick agreement on the simple issues, perhaps as early as this week's talks, following signals that Beijing is prepared to offer some concessions. But speaking to reporters in Beijing yesterday, Mr Tsui quoted the Vice-Premier as saying that it was impossible for China to further retreat from its bottom line regardless of Britain's attitude. ''The Chinese side stands firm no matter what attitudes the British will take,'' Mr Li was quoted as saying by Mr Tsui, who is also a member of the Preliminary Working Group for the Special Administrative Region Preparatory Committee. On the relationship between economic and political matters, Mr Tsui was told that it was difficult to separate the two. Mr Li said he hoped Britain would adopt a reasonable attitude so China could co-operate with Britain to maintain stability and prosperity in Hong Kong. The Governor's spokesman Mike Hanson said last night: ''We have entered the talks in good faith. We have tried very hard to reach an agreement with the Chinese side. ''If these remarks [by Mr Li] have been accurately reported, they do not suggest the Chinese side is willing to match our good faith and sincerity,'' Mr Hanson said.