Campaigners are marching to Downing Street to ask Tony Blair for his support in ending Chinese rule in Tibet.
Members of the Free Tibet Campaign were marking the 44th anniversary of the exile of Tibet’s spiritual leader, the Dalai Lama.
Their letter to Mr Blair asks him to put pressure on China to negotiate openly with the Tibetan government in exile.
The Prime Minister is due to visit China in late April, just weeks after the Communist Party elects its new president Hu Jintao.
Anne Callaghan, of the Free Tibet Campaign, said: “In this climate of fear and uncertainty over a possible war with Iraq, we believe the Prime Minister has a duty to reward the Tibetans’ peaceful struggle for freedom.
“He should insist that Beijing drops its pre-conditions for negotiations with the democratically-elected Tibetan Government in exile.”
China sent its army into Tibet in 1950, claiming the country was historically a Chinese province.
The Dalai Lama fled Tibet in 1959 after a revolt against the Chinese failed.
More than 120,000 Tibetans have followed him into exile in India.
