In a letter to the trade secretary, Liz Truss, the organisation says the UK has – since the BSE crisis of the 1990s – “led a food safety revolution” to make it a world leader in protecting the public.
Sharing the full story, not just the headlines
But it warns: “This could all be at risk depending on the approach that the government takes when it begins a second round of trade talks with the US on Monday.
“Which? recognises the benefits of trade and the benefits that could come from a UK-US trade deal – but this cannot be at the expense of our food standards and consumer confidence in what we eat.”
No less than 72 per cent of the British public does not want chlorine-washed chicken and hormone-fed beef to be allowed on sale in the UK, its survey had found.
The protest comes after Downing Street revealed a previous pledge to maintain the ban on those US products had been dropped, as talks on a trade deal with Washington ramp up.
Instead, ministers are pushing a “dual-tariff” regime, which would impose higher levies on good that fail to comply with UK animal welfare standards, arguing that would make US exports uneconomical.
But Which? said it feared a “two-tier system” which would see cheap, lower-quality food made available in schools and NHS canteens for example.
“UK consumers have a legitimate fear that two decades of progress on food safety and animal welfare could be traded away in just two weeks of negotiations with the US,” warned Sue Davies, its head of consumer protection.
The latest news on Brexit, politics and beyond direct to your inbox
Register with your social account or click here to log in
The criticism reflects evidence that washing chicken in chlorine – as well as being an animal welfare issue – poses food safety risks because it does not remove bacteria and masks other dangerous practices.
That ban will be transferred to UK law at the end of the Brexit transition period in December, but Ms Truss has made clear it will be up to MPs whether to then lift it.
The government enjoyed an 80-strong majority and has refused to impose the same food safety standards in the Agriculture Bill currently going through parliament – despite a Tory revolt.
In her letter, Ms Davies wrote: “This weaker approach risks both destroying the public’s trust in trade deals and leaving our future national approach to food entirely compromised.
“We therefore urge you to listen to the British public who value the UK’s high food standards and ensure that they are upheld in the negotiations.”