Chinese Ambassador Zhang Junsai has written to Michael Danby, chairman of the Parliament's Joint Standing Committee on Foreign Affairs, Defence and Trade, to complain about the Labor MP's plans to attend the rally organised by the Australia-Tibet Council to mark the 50th anniversary of the 1959 Tibetan uprising against Chinese rule.

''The rally on 10 March will be another act of 'Tibetan independence' groups to pursue 'Tibetan independence', tarnish the image of the Chinese Government and impair China-Australia relations,'' Mr Zhang wrote to Mr Danby on February 27.

''I hope you will give careful consideration to this and refrain from attending the 'Tibetan independence' activity on 10 March.''

Mr Danby, who is a member of the All-Party Parliamentary Group for Tibet, said he still intended to speak at today's rally.

''I can assure you that my remarks to this gathering will be in conformity with my long expressed views,'' he wrote to the ambassador last Friday. ''These are that I do not support separatism in any region of China ... I do, however, support genuine autonomy for the people of Tibet, within the People's Republic of China, similar to the status currently enjoyed by Hong Kong and Macau.

''It is my sincere view ... that the current denial of genuine autonomy to the people of Tibet is the real cause of ethnic disunity and social instability in the Tibetan-speaking areas of China.''

The parliamentary group for Tibet, which includes Australian Greens Leader Senator Bob Brown, Liberal backbencher Peter Slipper and independent senator Nick Xenophon, has been seeking permission to visit Tibet for more than a year.

Sources close to the group said it was thought unlikely the Chinese authorities would ever agree.

Last November, pro-Chinese federal Liberal parliamentarian Michael Johnson was allowed to visit Tibet at the invitation of the Chinese Government.

Mr Johnson subsequently told the Chinese People's Daily newspaper that Western media reporting on Tibet needed less emphasis on human rights and a greater focus on economic progress.

The rally outside Parliament House this morning will be followed by a march to the Chinese Embassy in Yarralumla for a demonstration condemning the continued repression and human rights abuses in Tibet.