The government is wrong to consider locking us into EU SPS rules. The EU when we were in it designed rules to keep out better value safe food from our previous supply sources in Australia, New Zealand, the USA and Argentina. It used regulations and tariffs to limit imports.
At the same time it rolled out policies to disadvantage UK farms and get us more dependent on EU imports. They refused to give us sufficient milk quota , forcing us to buy value added products like yoghurt from the continental countries who were granted bigger quotas. They used disease in UK cattle to have a long and comprehensive ban on UK beef. They gave grants to get the UK to rip out orchards so we could import more continental fruit.
The current argument is about SPS regulations. The EU insists under its Sanitary and Phytosanitary rules that all meat and dairy export consignments into the EU require a new vet certificate to say the animals were in good health. This is an added cost and slows things down. Previously it was sufficient to run compliant animal husbandry and to notify immediately if a farm had an animal health problem. The UK can of course insist on similar controls to those the EU imposes . If we did so the EU would be more interested in reducing the burden.
Uk exports of meat, cheese and butter to the EU have always been modest. We import three times as much food and drink from the EU as we export to them. It would be wrong to give away our ability to shape our own food safety rules and import from places other than the EU where the product is better value.