The British government banned two ministers from meeting the Dalai Lama during his visit this summer, prompting them to accuse London of bowing to pressure from Beijing, it emerged on Monday.
Tim Loughton and Norman Baker, who both have long-standing ties to Tibet, were barred from attending a private lunch in June with the Tibetan spiritual leader in the London apartment of House of Commons speaker John Bercow.
In a letter in July to Prime Minister David Cameron, which has been leaked to the media, the pair expressed their "concern and annoyance with regard to the inflexible instruction given last week to ministers, prohibiting any contact whatsoever with the Dalai Lama during his visit to the UK".
They said a note from the Foreign Office warning of the sensitivies surrounding Tibet and China did not justify a "blanket prohibition on a minister meeting a religious leader in private in a non-ministerial capacity, and we think this crossed a line", according to a copy printed in the Daily Telegraph.
"The note is tantamount to saying that British foreign policy on Tibet is whatever China wants it to be," they wrote.
"It completely ignores the fact that His Holiness is a spiritual leader only, and no longer holds a political position, and is frankly just plain wrong."
They said they were put under "tremendous pressure" not to attend, reportedly from Cameron's aides and a Foreign Office minister.
The British government said in a statement it was important to "strike a balance between taking a clear position on Tibet and sustaining broad-based engagement with the Chinese government".
While Britain regularly expressed its concerns about human rights in Tibet with Beijing, "it is only through engaging China that we can help bring about positive change to human rights in China".
The Dalai Lama visited Britain twice this year.
"We made clear in advance to the Chinese government that British ministers will decide who they meet and when they meet them - irrespective of Chinese lobbying," the British statement said.
"It was never intended that any minister would meet the Dalai Lama on his second visit."
Loughton, a member of Cameron's Conservative party, lost his job as children's minister in September. Baker is a junior transport minister and a member of the Liberal Democrats, the junior coalition partners.
Both of them had previously met the Dalai Lama in Dharamsala.