Britain is facing into a "bloodbath" over a proposed trade deal with the US, an EU commissioner has warned.
Phil Hogan, agriculture and rural development commissioner in Brussels, also derided Theresa May's plan to strike agreements with countries around the world as a fanciful notion of a new British Empire.
Speaking at a Brexit conference in Dublin, he suggested Trade Secretary Liam Fox's push for cheap food imports from the US already signals a lowering of standards that risks a revolt from the public.
"Liam Fox is pushing for agriculture to be included in such (UK-US trade) discussions, claiming that Americans have been eating hormone beef and chlorine chicken perfectly safely for years, so what's all the fuss about?" he said.
"Would British farmers and consumers accept hormone beef and chlorine chicken on their supermarket shelves?
"I seriously doubt it. There may yet be a bloodbath over these issues."
Mr Hogan told the conference, organised by the Irish Farmers' Association, that countries within the EU "can rest easy in the knowledge that our negotiating weight in trade deals means that our partners rise to our standards, rather than us lowering to theirs."
A pronouncement by Mrs May, on the day Article 50 was triggered, that Britain will strike similar deals with other countries outside the EU was also questionable, he suggested.
"This aim, based on notions of an Empire 2.0, is somewhat fanciful when you look at the trade-offs the UK would have to submit to in order to do deals around the world," he said.
However, he added he was encouraged by the Prime Minister's remarks in more recent weeks now that "a greater sense of realism" had kicked into the Brexit debate.
Mr Hogan said he hoped June's general election would strengthen Mrs May's hand in facing down the "looney voices on the right of the Tory party" and that Britain would remain within the EU's Customs Union.
"It is my hope that, over the course of the coming months, the British Government will recognise that the best way to maintain the freest possible trade in goods such as agri-food products is to remain in the Customs Union, and that sense will prevail," he said.