Farmers have called on the British public to lobby their MPs as a way to avoid 'long-term adverse impacts' for UK food security and consumer health.
The call comes as a result of the government blocking an amendment to the Agriculture Bill, which would have banned food imports produced to lower standards in the event of any trade deal.
The Farmers' Union of Wales (FUW) says it is 'not too late' to lobby MPs before the Bill - which soon reaches the House of Lords committee stage - becomes law.
The union's president Glyn Roberts said: “You can send them a letter making it clear that UK consumers and food producers deserve better, and let your voice be heard.”
The Bill has, since being drafted by the government, included a clause that would ensure imported organic food from an overseas country is produced to standards equivalent to the UK's.
But an attempt to introduce a similar clause requiring that any food product imported be produced to standards equivalent to the UK was opposed by the government and defeated during the Third Reading of the Bill on the 13 May.
Mr Roberts said farmers found this 'completely unacceptable' as the government had previously committed to upholding UK standards.
"The principle of maintaining UK standards and protecting consumers, farmers and food producers from sub-standard imports has cross-party support," he said.
"If the public wants to help - a good way is to join our campaign to stop this madness.”
Farmers, as well as consumers, conservationists and animal welfare bodies, are united in supporting such an addition to the Bill. The FUW added that the general public were 'overwhelmingly' behind it.
But failure to include an amendment supporting British standards before the Bill receives Royal Assent could have 'long-term adverse impacts' on British farming.
“I would urge anyone to ask their MP to make sure they do all they can to ensure that the proposed Clause 2 or an equivalent addition to the Bill is ultimately included before it receives Royal Assent," Mr Roberts added.
“Failure for such a change to be made to the Bill will have long term adverse impacts for UK food security, consumer health, our agriculture industry, global animal welfare and ecosystems as well as resulting in significant political damage for the government.”
Elsewhere, the NFU's food standards petition is nearing 1 million signatures. As of Tuesday 16 June, over 980,000 people have signed.