China has been compared to Nazi Germany and accused of a "programme of ethnic cleansing" against the Uighur people in a letter signed by more than 130 MPs and peers.
The cross-party letter, which features prominent Labour and Conservative members, said the evidence that had been circulating in British media about the treatment of Uighurs in China's Xinjiang province was "truly chilling".
The Uighurs are a largely Muslim minority in China, with the majority of the 11.3 million living in Xinjiang.
The letter was addressed to China's ambassador to the UK Liu Xiaoming and referenced when the BBC's Andrew Marr showed him footage of large numbers of people blindfolded, kneeling and shaven waiting to be loaded on to trains.
The letter, which includes Lib Dem leader Sir Ed Davey, said: "The similarities between this video and historical footage of Nazi concentration camps are truly chilling."
It went on to say: "The Chinese government's actions must be stated for what they are: a systematic and calculated programme of ethnic cleansing against Uighur people."
There has been growing international pressure on China to reveal more about its treatment of Uighurs with global media slowly picking up more and more evidence of ethnic cleansing.
Last week the United States demanded China ended its "ongoing campaign of repression against Uighurs."
Secretary of State Mike Pompeo repeated his claim that the Chinese Communist Party’s record in Xinjiang is the "stain of the century"
There is evidence of systemic sterilisation and forced abortions being carried out against Uighurs.
Last week ITV's Emma Murphy spoke to a Uighur doctor who said she had taken part in population control against her people.
She said she participated in at least 500 to 600 operations on Uighur women including forced contraception, forced abortion, forced sterilisation and forced removal of wombs.In the letter, which was led by Labour MP Siobhain McDonagh, they referenced such actions.
It said: "It has even been reported that birth rates have fallen by 60% in some Uighur areas."
Uighurs that have managed to escape Xinjiang have reported losing contact with their loved ones and demands they come back from Chinese authorities.
Last week Nursiman Abdureshid, a Uighur living in Turkey, told ITV News she had lost contact with all of their family in China.
She said: “When you listen to camp survivors, when they describe the torture in the camps and the prison I just can't stand it because I cannot imagine my fathers and my brothers and my mother also facing such torture".
Last week an independent tribunal was set up in London to investigate the treatment of Uighur's and if it constitutes genocide.
China has repeatedly denied the allegations that it is mistreating its Uighur people.