Chickens washed in chlorine during processing is common practice in the United States - but in Britain many are horrified at the prospect, and it's fast become a campaign issue.
Debate about the issue threatened free trade deals between the two nations late last week, and contributed to Europe's rejection of the Transatlantic Trade and Investment Partnership (TTIP).
For many Brits, the sale of chlorine-washed chickens is abhorrent, and debate over the practice has revealed further discrepancies between the two countries about how animals are treated.
The Daily Mail reported that while there is no legal requirement to wash chickens in chlorine or other disinfectants, 97 percent of US chickens are cleaned this way after slaughter.
US chickens being sold in Britain after a post-Brexit trade deal ignited significant debate in Cabinet, where Environment Secretary Michael Give denounced the move while Trade Secretary Liam Fox said the chlorine-rinsed meat was safe.
Mr Fox met with politicians and businessmen in the US last week, during which he indicated that he would be in favour of ditching the EU's ban on importing chicken from the US if it proved to be a barrier to securing a post-Brexit trade deal.
Mr Fox said the British media were "obsessed with chlorine washed chickens".
This statement sparked anger from the public and other ministers, and highlighted the difficulties Britain will face in initiating deals with other foreign powers once they exit the EU in 2019.
In New Zealand, like the US, chickens are routinely washed in a chlorine solution during processing.
Food safety consultant Roy Biggs told Radio New Zealand processors here wash chicken in chlorine for safety reasons.
Mr Biggs is a former chair of the Association for Food Protection and was Tegal Food's regional technical manager for the Lower North Island.
Chickens need to be cooled after slaughter, and he said there are two ways of doing this around the world; air chilling, which is used in the UK and EU, and water chilling, using an iced water and chlorine solution.
Water chilling is more efficient, he said, and the reason for chlorinating the water is to control the transfer of bacteria between chickens.
Mr Biggs said the benefits of chlorinated water to wash chicken were around food safety and the threat of bacteria-borne diseases like Salmonella and Campylobacter.
He said 99 percent of chickens in New Zealand would have been cooled in chillers using iced water with chlorine.
From 2011-2017 there's been less than 0.5 percent of bacteria on chickens, he said.
Regarding food safety discrepancies between organic chicken or otherwise, there's no difference, he said, "They all have opportunities to pick up organisms like campylobacter".
"Consumer perception is more powerful than science. People perceive this is probably not a good idea, which is incorrect."
Jim Sumner, president of the US Poultry & Egg Export Council, said US chickens are washed with chlorine to make them "extra safe" for consumers because it guards against bacteria.
He said the process was not harmful to consumers, and that "sometimes [animal welfare] organisations do not have a thorough understanding of the process or scientific fact."
Another reason why poultry in the US is chlorinated is that farmers are not required to vaccinate against diseases such as Salmonella. Britain and the EU have widespread vaccination programmes.
Supporters of chlorine-washed chicken point out both US and European food safety authorities have declared the chemicals used to wash chickens in the States as not posing any risk to human health.
But Jaydee Hanson, a senior policy analyst at the US Center for Food Safety, said the chemicals are "basically like the ones we put in our toilets to clean them".
"The question is why are chickens so contaminated in the first place? And the issue is that we are not doing a good job of raising chickens."
Shraddha Kau of the British Poultry Council said they strongly reject any move to import chlorine-washed chickens as part of a deal in trade negotiations with the US.
"Chlorine is used as a catch-all. It is an approach which means it doesn't matter how badly you treat your chicken, you can just clean it away at the end of the process."
There are concerns that if American chicken is allowed into the country, British farmers will be forced to dilute their welfare standards to compete with the cheaper product.