The Government has admitted for the first time that Uighurs are being targeted by China on British soil “in an effort to intimidate them into silence”.
The problem is now so serious that it risks becoming a diplomatic incident after ministers complained directly to the Chinese embassy in London.
On Saturday night the Foreign Office urged British Uighurs to call the police immediately if they felt they were being intimidated by Chinese officials.
Concerns about intimidation of British Uighurs on UK soil by Chinese officials were first exposed in The Telegraph last August.
The latest development was condemned by campaigners who demanded greater protection for British Uighurs from Chinese intimidation on UK soil.
More than a dozen MPs are expected to write to the House of Commons Speaker Sir Lindsay Hoyle on Monday to demand an urgent question in the House of Commons.
It comes after global experts last week accused the Chinese government of violating every provision in the United Nations genocide convention for its treatment of the estimated 12 million Uighurs in Xinjiang province.
However, official confirmation of the UK Government’s concerns was set out in an overlooked written answer in Parliament last week.
Nigel Adams, a Foreign Office minister, said: “We are aware of reports of members of the Uighur diaspora – including in the UK – being harassed by the Chinese authorities in an effort to intimidate them into silence, force them to return to China, or co-opt them into providing information on other Uighurs.
“The Government regards such activity as unacceptable and has raised our concerns directly with the Chinese Embassy in London.
“The FCDO continues to monitor the situation closely and we urge anyone affected in the UK to contact the police.”
A Foreign Office source added: “We are in regular discussions with the Chinese embassy including on issues of concern.”
The scale of intimidation is laid bare by Rahima Mahmut, the UK director for the World Uighur Congress, in an article for The Telegraph in which she told how “today Uighurs in Britain are silenced”.
She said: “One British Uighur woman revealed how she received text messages everyday from Chinese police forces urging her to spy on the lives of her other Uighur in the UK.
“The texts would always contain the ominous warning: ‘remember your mother and your sisters are with us’”.
A British Uighur student told how she was called to the Chinese Embassy in London and “pressured into writing an opinion piece for a newspaper declaring there to be no re-education camps in Xinjiang”.
Ms Mahmut said the student was told: “Remember, your mother and other family members are still in China.”
Ms Mahmut also says the UK should ban “goods made from Uighur forced labour”. The Uighur region produces 20 per cent of the world’s cotton.
She added that the Government should stop blocking “the ‘genocide amendment’ to the Trade Bill – a move which would see a panel of British judges giving an impartial legal opinion on the alleged abuses”.
Labour MP Afzal Khan, the vice chairman of the All Party Parliamentary Group on Uighurs, told The Telegraph: “Reports now show that Chinese officials are intimidating Uighurs into silence after speaking out.
“The Government must raise this urgent matter with Chinese officials and offer witnesses protection to ensure they are able to testify safely, without fear, about the atrocities suffered.
“It is unacceptable that members of the Uighur diaspora in the UK and elsewhere are faced with harassment and abuse.
“Words of condemnation by the Government are not enough, action is desperately needed.”
The Chinese Embassy in London did not respond to several requests for comment from The Telegraph.
Last August The Telegraph told how Simon Cheng Man-kit, a former British consulate employee in Hong Kong who was tortured by Chinese secret police, said he had been followed at least three times in the last two weeks.
Mr Cheng, who has been granted asylum in the UK, has been vocal about eroding freedoms in Hong Kong.
A threatening email also arrived in Mr Cheng’s inbox saying in the subject line “Chinese agents will find you and bring you back”.
Separately Dominic Raab on Saturday said China was not complying with the Sino-British Joint Declaration after Beijing’s latest move to tighten control over Hong Kong with new powers to crack down on the pro-democracy movement.
He said the move was part of a “pattern designed to harass and stifle all voices critical of China’s policies” and marked the third breach of the legally binding Joint Declaration in less than nine months.
The Sino-British Joint Declaration was signed in 1984.