CHINESE Vice-Premier and Foreign Minister Qian Qichen is making tentative plans to visit Britain next year in a move which would be seen as marking the start of a thaw in relations over Hong Kong. Mainland officials have told British Ambassador to Beijing Sir Len Appleyard that Mr Qian is interested in going to London and may be able to do so during the first half of 1995. The conciliatory message came after Britain made major concessions for the recent signing of an agreed minute on airport financing. No arrangements have been made or dates discussed and Whitehall officials remain cautious, fearing hardliners in the mainland leadership may block Mr Qian's plans. But in a further sign of a thaw, China has lifted a virtual ban on visits by senior British ministers by indicating that Michael Heseltine, President of the Board of Trade and one of the most important cabinet members, will be welcome in Beijing early next year. Mr Qian's trip, if confirmed, would be his first to London since March 1992 - four months before Chris Patten became Governor. The Chinese leader is expected to have intensive discussions with Foreign Secretary Douglas Hurd on Hong Kong, and may be invited to Downing Street to meet Prime Minister John Major. Such a visit would also mark the end of China's 21/2-year boycott of Britain. A Foreign Office spokesman in London said no senior mainland official has visited Britain since Vice-Premier Zhu Rongji made headlines when he was reported to have cast doubt on the continuing validity of the Joint Declaration during a trip in November 1992. But it will come too late for the two countries to meet this year's obligations under the 1991 Memorandum of Understanding on the new airport, which requires the foreign ministers to meet twice a year. Despite the new developments there is no sign of a similar rapprochement with Mr Patten's administration. A senior Hong Kong Government official said Chief Secretary Anson Chan Fang On-sang's repeatedly stated wish to visit Beijing was not even discussed during the recent diplomatic contacts - and there was little chance of it going ahead soon. Bill Dickson, the Foreign Office spokesman in Hong Kong, declined to comment, saying diplomatic exchanges between Britain and China were confidential. But he admitted Britain hoped there would be several ministerial visits between Beijing and London in 1995, although 'we are not yet at the stage of discussing specific dates'. A source in London said Mr Qian's interest in a visit came after many months of refusing invitations. Mr Hurd received no positive response when he floated the idea in a message sent with Minister for Hong Kong Alastair Goodlad during his trip to Beijing in July. The invitation was repeated when the foreign ministers met in New York in September and Mr Qian gave the first sign he might consider a visit. But it was only after the agreed minute was signed on November 4 that Beijing intimated it was seriously interested. Ties have already begun to improve with the relatively low-ranking Vice-Minister of Finance, Zhang Youcai, meeting Mr Hurd and Mr Goodlad in London two weeks ago. Mr Heseltine's tentative invitation to Beijing is seen as another move towards better relations. China had earlier refused to receive him, insisting his plans for a visit this autumn were 'not convenient', despite a personal plea from Mr Hurd during the New York meeting. Trade Minister Richard Needham was also snubbed when he tried to visit China last month. But now the ban appears to have been lifted, visits by other British ministers are under discussion, including one by Transport Minister Brian Mawhinney.