SENIOR British politicians have started to turn against Hongkong Governor Mr Chris Patten's political reform package, after an intensive lobbying campaign by the Chinese Embassy in London. Although the British Government publicly remains committed to backing Mr Patten, the pressure of Chinese antagonism to his political blueprint is beginning to take its toll on the cross-party consensus. The lobbying of MPs in both the government and the main opposition party by the Chinese has cast new doubts on the future of Mr Patten's reforms and could lead to a realignment of British politicians on the controversial issue. Last Monday China's ambassador to London Mr Ma Yuzhen held a three-hour meeting with shadow foreign secretary Mr Jack Cunningham and his deputy, the spokesman responsible for Hongkong, Mr Allan Rogers. After the meeting Mr Cunningham and Mr Rogers both agreed to visit Beijing for further talks about Hongkong, probably in May. Mr Ma has also held meetings with other MPs and several have reportedly accepted invitations to travel to Beijing within the next few months, including two senior members of the Labour Party who are expected to visit China over Easter. A shadow minister who accepted the Beijing invitation, said he and some of his colleagues were beginning to change their minds about supporting the government's backing for the Patten package. He said many Labour MPs believed the future for the people of Hongkong would be better served by reaching an agreement with China, rather than ''blindly'' supporting Mr Patten. Another senior Labour Party official said there was not likely to be an early public change of stance by the Labour Party, but at the same time he said Labour was ready to support any diplomatic way out of the current impasse between London and Beijing. A senior Conservative backbencher experienced in Hongkong affairs echoed the Labour Party's political dilemma on the issue: ''There is no way Conservatives can come out publicly against Mr Patten. But we do take on board the problems of the Chinese Government, and we think that the Patten package has to be watered down.'' Representatives from both parties declined to go on the record but a Labour Party official said he believed his party would soon go public on the issue. The doubts of members on both sides of the fence and Mr Ma's talks with Labour MPs coincide with a series of meetings which the British Government is having with Conservative members to try to secure support for the Patten package. The Foreign Officer Minister responsible for Hongkong, Mr Alastair Goodlad, last week held a series of briefings for Conservative backbenchers on the territory. At the same time, Foreign Office officials are insisting that there are no behind the scenes talks between Britain and China over Hongkong, contrary to reports and rumours in Hongkong. They denied last week there had been any contacts beyond routine links between the two foreign departments and also deny any recent significant talks or other contact between the foreign ministers.