AFTER a year of highly sensitive diplomatic wrangling, British Airways (BA) and Taiwan's EVA Airways have been given permission to operate direct flights between London and Taipei. EVA, a subsidiary of the giant Evergreen shipping and industrial group, has yet to announce firm plans but is likely to fly to Britain three times a week from late March or early April by adding an extra flight and leg to its existing twice-weekly service to Vienna. BA will operate a twice-weekly service between London and Taipei and has traffic rights to pick up and drop passengers in Hongkong en route. Flights will depart London Heathrow airport on Mondays and Saturdays from March 29, continuing on from Hongkong on Tuesdays and Sundays. Return flights will depart from Taipei for Hongkong and London on Tuesdays and Sundays. The British airline's management has had to go to great lengths to avoid a diplomatic row with China and risk possible repercussions. It will operate the service through a subsidiary set up for the purpose, British Asia Airways, and will remove the Union Flag from aircraft livery. Lord Caithness, Britain's Minister of State for Aviation and Shipping, who announced the new air links between Britain and Taiwan, said the British Government had consulted China. He also went to lengths to state that there had been no contacts of any official nature between his government and the Taiwan authorities, nor had any official agreements between the two been signed. In a bid to pacify the Chinese Government, Lord Caithness reaffirmed the British position that it recognised Taiwan as a province of the People's Republic of China. Services will operate under a purely commercial arrangement between British Asia Airways and the Taipei Airlines Association. The British Government said the new air route would encourage the further development of commercial links with what it described as ''this important trade partner''. Mr Roddy Wilson, BA Far East general manager, said: ''Taiwan is a growing market commercially for Britain. ''We have been considering opening up this route for some time, but only started thinking positively about it a year ago.'' He added: ''We realise it is a politically sensitive route because of the claim by China of sovereignty over Taiwan. ''We have learnt from the examples of other airlines already operating in and out of Taiwan.'' Although there has been no formal indication from Beijing as to whether or not it approves of the move, a BA source said the airline would not be going ahead with the deal if it thought it would jeopardise its existing good relations. Flying rights over China have been difficult to come by at the best of times. While American carriers Northwest and United Airlines operate in and out of Taiwan under their own names, airlines from nations more sensitive to the China-Taiwan political situation have distanced themselves by operating through subsidiaries. Aircraft used by both EVA and British Asia Airways will not fly any flags, insignia or livery with official connotations. British Asia Airways' Boeing 747-400 aircraft will have the new company name painted on it, probably in the company colours of red, white and blue, but there will be no Union Flag. BA was clearly hoping agreement could have been reached earlier as its current timetable, covering the October to March half-year, details a non-existent flight BA035 from London Gatwick via Bombay and Hongkong to Taipei. EVA uses Boeing 767s on its existing twice-weekly flights to Vienna via Bangkok, but the rapidly expanding airline is now in the process of accepting new 747-400s into service and will clearly be keeping an eye on its European load factors in the months ahead. Britain is only the second European Community member, after the Netherlands, to permit direct passenger flights into Taiwan.