Henry Dimbleby – who is calling for snack taxes to cut obesity – also echoed fears that the controversial no-restrictions deal struck with Australia will be a model for deals with much bigger food exporters.
“If they do this kind of no-tariff, no-quota deal with Brazil or the US, it would not only export huge amounts of environmental and animal welfare harms – making what we’re doing pointless in this country – but it would lay waste to the livelihoods of a large percentage of our farmers too,” he said.
Mr Dimbleby pointed out that, while the government had said it would protect post-Brexit standards, it had not said “how it’s going to do that, or what those standards are”.
He warned there was “huge jeopardy for our food supply and for our farmers” in adjusting to leaving the EU, which could be exacerbated.
The adviser said he hoped it was not the prime minister’s wish to strike trade deals at almost any cost, adding: “Certainly it’s not in the Conservative manifesto.”
The warning comes after the Australia deal alarmed farmers because, contrary to pledges of 15 years’ protection, tariffs will be scrapped immediately on imported beef and lamb.
There is also anger that MPs will not – as The Independent revealed – be allowed to scrutinise the text until towards the end of the year, when they fear it will be too late.
Criticising that secrecy, Mr Dimbleby told BBC Radio 4 the Australia deal “has an animal welfare chapter”, but warned: “We haven’t seen what’s in it.”
Announcing the deal last month, the trade secretary Liz Truss repeatedly refused to guarantee that meat treated with antibiotics, or pesticides, will continue to be barred.
Australia uses much 16 times more antibiotics for poultry farming than Britain, allowing farmers to crowd animals together to make meat cheaper – but sparking criticism about their conditions.
Ms Truss accused MPs raising fears about antibiotics of demanding “regulatory harmonisation” and saying only: “We are not lowering our food import standards as a result of this deal.”
Joe Biden’s administration has slammed the brakes on talks on a US trade deal, but Ms Truss is visiting the country for a week, as UK hopes of progress endure
In the Commons, as fears were raised about Brazil allowing the Amazon rainforest to become a “source” of carbon emissions, her deputy Greg Hands said: “We are not currently negotiating a trade agreement with Brazil.”
Mr Dimbleby spoke out as Robert Jenrick, the communities secretary, suggested the government will reject his proposals for new sugar and salt taxes on junk food.
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