ANY further concessions by China in the Sino-British talks on electoral reform would only be seen as an act of cowardice in the eyes of stubborn British colonists, according to the pro-China newspaper Ta Kung Pao. In its editorial yesterday, the paper said the British Government had exhausted all means in the past 17 rounds of talks to put its own people into the future Special Administrative Region government, thus disrupting Hong Kong after 1997. ''Throughout the match, the British side has not budged an inch,'' it said. The paper added that China had already demonstrated the greatest degree of tolerance and patience. Another pro-China paper, Wen Wei Po, said that Britain had been determined from the outset not to be bound by the outcome of the negotiations. The paper said Britain was only employing ''delaying tactics'' when it agreed to negotiate with China. United Democrat chairman Martin Lee Chu-ming said in Canada that he had received reassurances from the Canadian Government that it would continue to support Hong Kong's desire to enjoy ''a high degree of autonomy'' as laid down in the Joint Declaration. The Canadian Government also pledged that Canada would be a dependable partner of Hong Kong as the territory faced new challenges in the run-up to 1997, he added. Mr Lee will fly to Washington today and will meet representatives of the United States Government and Congress.