Senior cabinet ministers are set to meet on Thursday morning to discuss the proposed deal – with several ministers believed to be against the plan pushed by international trade secretary Liz Truss.

Labour’s shadow international trade secretary Emily Thornberry warned the government not to not to strike a deal just to “prove a political point” about Britain’s post-Brexit economic independence.

“I don’t think there’s likely to be a country around the world that is going into a deal saying, ‘Well yeah, it may decimate our farming industry, but we need to have a deal in order to prove some political point’,” Ms Thornberry told Sky News on Thursday.

The Labour frontbencher added: “Why would we want to undermine our farming industry? We have high standards in our country of animal welfare and food production, and we don’t want that undermined by cheap imports of food not produced to the same standard.”

A major rift has reportedly opened in cabinet over a deal being negotiated by Ms Truss with Australia, over concerns about the damage done by granting tariff-free access to UK markets.

Environment secretary George Eustice and Cabinet Office minister Michael Gove are understood to be against allowing tariff-free access, with Ms Truss and Brexit minister Lord Frost pushing for it.

The Nation Farmers’ Union (NFU) and other farming groups have warned ministers they would “struggle to compete” if zero-tariff trade on lamb and beef went ahead.

Both the SNP and Plaid Cymru have also voiced strong opposition to the plan, arguing that it would undercut Scottish and Welsh farmers.

On Wednesday, the SNP’s Westminster leader Ian Blackford told Mr Johnson he was preparing to throw the farming and crofting community “under the Brexit bus”.

Plaid Cymru’s international trade spokesperson Hywel Williams said a zero-tariffs deal with Australia would “devastate the Welsh farming industry for generations”.

He added: “The prime minister is again showing his willingness to sacrifice Welsh agriculture for cheap political gain.”

However, Ms Truss has insisted British farmers “will not be undercut” by any agreement with Australia, amid fears over imports of lamb and beef.

Speaking to MPs on the Commons International Trade Committee on Wednesday, she said: “I have had discussions with the National Farmers’ Union, I’ve been very clear with them that … British farmers will not be undercut by unfair practices from elsewhere.

Ms Truss added: “We will make sure in all the deals we do that British farming thrives and I’m absolutely confident that will be achieved through the Australia deal.”