Farm leaders have expressed grave concerns for the future of UK agriculture after Boris Johnson’s government signed a free trade deal with Australia, according to reports.

Prime minister Mr Johnson and Australian PM Scott Morrison agreed the broad terms of a free trade agreement (FTA) over dinner on Monday evening (14 June).

The deal was reportedly agreed by the two leaders at Downing Street when they dined over Scottish salmon, Welsh lamb, washed down with Australian wine.

Responding to news of a deal, Glyn Roberts, president of the Farmers’ Union of Wales said: “We have grave concerns that we could end up with a deal that’s catastrophic for animal welfare, the environment, our family farms and our food security – and that it will be set in stone.”

Mr Roberts urged MPs to “do all they can to fully scrutinise and have a say” on the UK-Australia trade deal. Ministers say the Trade and Agriculture Commission will be given time to pore over the detail and report back its findings.

Mr Roberts said MPs must take warnings extremely seriously about the implications of a trade deal that sets the UK on a permanent legally-binding course to open us up to food produced to lower environmental and welfare standards, and undermines our food security and the viability of our family farms.

“MPs must do all they can to prevent a culture of ‘ignore the warnings, get it done and deal with the consequences later’ predominating when it comes to this and other trade deals,” he added.

UK farm leaders have also expressed concerns about lower animal welfare standards on Australian farms.

These include the routine use of antibiotics to counter infections in feedlots and the practice of “mulesing”, whereby sheep have their rear ends sliced without anaesthetic to produce scar tissue as a means of controlling fly infestations.

Farmers in Australia are allowed to use growth-promoting hormones in cattle, and they have access to a number of pesticides that are banned for use in the UK, including looser restrictions on neonicotinoids.

International trade secretary Liz Truss has said that the import of hormone-injected beef will not be allowed to enter the UK market – and this will not change under the terms of any FTA.

The UK government wants tariffs on Australian food imports to be phased out over 15 years to allow British farmers to adjust, but Australia is pushing for a shorter, five-year period.