Labour has called on the government to ensure proper legal action is being taken against UK companies found to be doing business with overseas PPE suppliers accused of “abhorrent” modern slavery practices.

Bill Esterson MP, the shadow minister for international trade, has written to the attorney general seeking assurances “that the Crown Prosecution Services (CPS) will continue to prosecute all instances of modern slavery in the private sector”.

It was also revealed that Whitehall had identified companies suspected of forced labour as long ago as November 2019 – with further concerns about Malaysian glove suppliers highlighted by a UK diplomat during the peak of the pandemic.

In his letter to Michael Ellis QC MP, the attorney general, Mr Esterson wrote: “If the government cannot even eradicate modern slavery from its own supply chains, how can we trust your department to properly prosecute companies trading in the UK who are engaging in these same abhorrent practices?”

Just five months after the Home Office announced “powerful new measures” to tackle modern slavery risks in the UK’s supply chains, The Independent found that healthcare workers are using medical gloves manufactured by Brightway Holdings.

Brightway is facing 30 charges and a fine over the alleged failure to comply with housing standards for workers. It said the workers had been housed in hostels, acknowledged there was “congestion”, and said it was improving employee living conditions.

In November 2019 – long before the pandemic took hold – the Home Office produced a report on the glove-manufacturing industry in Malaysia that concluded “corruption is endemic in the recruitment systems of Malaysia and migrant worker source countries, and touches every part of the recruitment supply chain”.

Mr Esterson told The Independent: “The government must make sure it isn’t buying PPE made with slave labour. Otherwise, they are just confirming that the Conservatives will always put commercial interests ahead of human rights.”

He also highlighted how the government had voted down an amendment to the Trade Bill which would have stopped the UK trading with any country guilty of genocide.

The vote came after the House of Lords passed amendments targeted at preventing a deal with China while it remains under accusation of committing genocide against the Uighur Muslims of Xinjiang province three times.

The so-called “genocide amendment” to the government’s Trade Bill was defeated by 318 votes to 300 in the House of Commons, despite passionate speeches in its favour from Tory MPs.

Nusrat Uddin, a lawyer specialising in trafficking and labour abuses, said that the government needed to improve transparency in UK supply chains and that the Modern Slavery Act 2015 was not fit for purpose.

“The act requires certain companies, and soon public bodies, to publish steps they have taken to tackle modern slavery in their supply chains,” she told The Independent earlier this month.

“However, there are no set standards upon which those steps are assessed, and so even if companies are taking ineffective measures, they still fulfil government requirements.”

A spokesperson for the government said: “All those who sub-contract orders of equipment for the NHS must fully understand their supply chains and operate responsibly. We will not award contracts to those who fall below these standards.”