EU commissioner for agriculture Phil Hogan has hit out at a 'high level of delusion' in the UK over Brexit.
Mr Hogan called for Britain to remain in the customs union in order to significantly mitigate the impact of Brexit on Ireland and reduce risks on trade.
Speaking to the Financial Times, he also dismissed Liam Fox's trade deal preparations: "Barrier-free trade in goods and services with the EU has worked more than any number of hypothetical trade agreements that Mr Fox talks about around the world.
"They're talking about being a soft Brexit but they're acting in the negotiations in a way that can only lead to a hard Brexit.
"If there is an appetite for a pragmatic and reasonable outcome to a free-trade agreement, well then membership of the customs union would make a significant contribution to this."
UK farming unions are concerned that the influx of low quality imports will mean British farmers will struggle to compete.
President of the Ulster Farmers' Union (UFU) Barclay Bell said: "Politicians must ensure that food standards are upheld and cheap, low quality imports are not permitted to undermine our industry.
"Countries wishing to trade with us must demonstrate they can meet the high standards expected by UK consumers."
The warnings came as David Davis, the Brexit Secretary, announced the UK will seek the same trading rules with the EU for an interim period, of perhaps three years.
