The Environment Secretary has said the UK should say “no” to chlorine washed chicken from the United States, in direct contradiction with the International Trade Secretary. Asked whether the UK should allow the import of chorine-washed chicken, “yes or no”, Michael Gove gave a straightforward answer.

“No. I made it perfectly clear, and this is something on which all members of the Government are agreed. We are not going to dilute our high food-safety standards or our high environmental standards in pursuit of any trade deal. Our position when Margaret Thatcher was Prime Minister, and our position now, is to be a leader in environmental standards,” he said.

On BBC Newsnight last night, Liam Fox, the International Trade Secretary, said there was “no health issue” with chlorine-washed chicken.

Asked about the practice of washing poultry carcasses in chlorinated water, Mr Fox said: “The European Union has said that [chlorine-washed chicken] is perfectly safe.

“The issue lies around some of the secondary issues of animal welfare and it’s perfectly reasonable for people to raise that but it will come much further down the road.

“We will want to ensure that the scientific advice that we have ensures proper protection for British consumers because dropping our standards is not the way for Britain.”

Mr Fox previously condemned media “obsession” with the issue, which he said would be only “a detail of the very end stage of one sector of a potential free trade agreement” with the US.

The House of Lords EU Energy and Environment Sub-Committee warned that animal welfare standards could be undermined if post-Brexit trade deals left UK farmers competing against less-regulated foreign rivals.

The peers also raised concerns about the “overwhelming reliance” on EU citizens in crucial veterinary positions and urged ministers to make sure the industry was able to fill those roles after Brexit.

The report said: “Our evidence strongly suggests that the greatest threat to farm animal welfare standards post-Brexit would come from UK farmers competing against cheap, imported food from countries that produce to lower standards than the UK.

“Unless consumers are willing to pay for higher welfare products, UK farmers could become uncompetitive and welfare standards in the UK could come under pressure.”

They warned that imports from lower-welfare countries could “undermine the sustainability of the industry or incentivise a race to the bottom for welfare standards – contrary to the wishes of the UK industry”.