The UK government acted unlawfully by not investigating whether some cotton imports come from Uyghur forced-labour camps in China, a court has heard.
Lawyers for the World Uyghur Congress said there were “reasonable grounds” to believe UK retailers had benefited from cotton made by Uyghurs held in China.
Rights groups say Xinjiang’s Muslim Uyghur minority are being persecuted and conscripted for forced labour.
Government lawyers said it needed more evidence of a link to be able to act.
Beijing strongly denies any abuses.
Around 20% of the world’s cotton is made in China, and Xinjiang cotton accounts for 85% of all Chinese cotton.
In the first of two days of hearings at the High Court in London, Mr Tom Forster KC, for the World Uyghur Congress and the Global Legal Action Network, said the case was “not remotely hypothetical” but concerned the UK government’s duty to investigate whether “dirty property” was entering the country from Xinjiang.
Sir James Eadie KC, representing the home secretary, HMRC and the National Crime Agency, said the government considered China’s effort “to silence and repress Uyghurs and other minorities in Xinjiang [to be] appalling”.
However, he said there needed to be a clear link between “the alleged criminality and its specific product” to investigate whether goods were made in a foreign prison.
“At best, the claimant’s case is that there is a compelling inference of a chance that a crime has been committed but it is unable to identify how, by whom, when, or where such an offence took place,” the government’s lawyers argued.
“The existence of a general statistical likelihood is not (nor has it ever been) a basis for any criminal investigation or the exercise of any coercive power.”
They said government agencies needed the discretion to decide whether an investigation was likely to succeed before allocating resources.
“In the present context of an investigation in which the Chinese government would be implicated, there is no realistic prospect of police-to-police (or agency-to-agency) co-operation or of evidence being obtained by way of mutual legal assistance from the Chinese authorities, for example.”
‘Enough evidence’
Mr Forster responded that the claimant was not alleging a crime had been committed, just that there was enough evidence to launch an investigation.
“No identified criminal property results in no investigation, which results in no identified criminal property.”
It is thought to be the first time a foreign court has heard legal arguments from the Uyghurs over the issue of forced labour in Xinjiang.
Rahima Mahmut, UK director of the World Uyghur Congress, told the BBC she had not seen her family in Xinjiang for almost six years.
She urged the UK government to follow the lead of the United States and pass legislation to ban cotton products thought to have been made in Xinjiang.
“A genocide is happening in my country,” she said. “This case is about accountability.
“For us this is a legal opportunity to go to the high court in this country to complain about the departments that have the responsibility to stop slave-laboured goods.”
Gearóid Ó Cuinn, director of Global Legal Action Network, said the UK government needed to match its strong rhetoric on China with action.
“Right now UK consumers are systematically exposed to consumer goods tainted by forced labour,” he said.
“Companies have categorically failed in their efforts to remedy this unacceptable situation and continue to trade in these illicit goods in broad daylight.”
A government spokesperson said it would be inappropriate to comment while litigation was continuing.
The hearing, before Mr Justice Dove, is due to conclude on Wednesday, with a ruling at a later date.