British lawmakers called for a United Nations inquiry into "serious human rights abuses" against ethnic minorities including Uyghur Muslims in north-western China.
China's Foreign Ministry has castigated a UK parliamentary group for calling for a boycott of the 2022 Beijing Winter Olympics over what it called "atrocities" in Xinjiang.
On Thursday the British parliament's Foreign Affairs Committee published an excoriating report on human rights in the Xinjiang Uyghur Autonomous Region.
"The evidence of serious human rights abuses — all endorsed by the Chinese government's central leadership and perpetrated against the Uyghur people — is irrefutable," the Committee wrote in an accompanying statement.
"These crimes include forced labour programmes, arbitrary detention in internment camps, cultural erasure, systematic rape, forced sterilisations, separation of children from families and a high-technology surveillance system."
Reports of mass detentions and other abuses of Muslim ethnic minorities in north-western China have alarmed the international community and prompted a number of recent statements at the UN.
In May this year Chinese officials announced they were winding down the so-called "re-education" camps in Xinjiang, in which 1.5 million people were thought to be arbitrarily detained in 2019.
But the UK has called for increased pressure on China to allow international observers access to Xinjiang in the wake of a welter of reports of human rights violations.
The Foreign Affairs Committee's report urged the UK government to "respect the view of the House of Commons that crimes against humanity and genocide are taking place".
It asked for a ban on all cotton products produced in Xinjiang to be considered, together with a boycott of the Winter Olympics scheduled for February 2022 and increased support for Uyghurs in the UK, proposing the UK form a network of "sanctuary states" for those fleeing China.
In the absence of access to Xinjiang, it also recommended a UN inquiry take place remotely and for the UK government to "engage in dialogue with the International Criminal Court about the feasibility of an investigation into crimes committed against the Uyghurs in Xinjiang and beyond".
The report drew instant criticism from Beijing on Thursday. Speaking at a press conference, Foreign Ministry spokesman Wang Wenbin implied the report was an attempt to subvert the Olympics.
"China firmly opposes the politicization of sports, and the interference in other countries' internal affairs by using human rights issues as a pretext," he said.
"Some people attempt to disrupt, obstruct and sabotage the preparation and convening of the Beijing Winter Olympic Games out of political motivation.
"All sectors of the international community, including the governments and Olympic committees of many countries, and the International Olympic Committee, have all expressed their clear opposition to such [a] practice, that is doomed to fail."