TRADE secretary Liz Truss said farmers would be "undermined" in a gaffe during questions from MPs.

The International Trade Secretary was answering a question from shadow trade secretary Emily Thornberry on farming standards, when she said: "Of course, in any trade deal, we strike we will be taking into account our high standards, to make sure our farmers are undermined."

The pair clashed over the issue of standards, after an amendment last month in the House of Lords to the Agriculture Bill, which attempted to stop the import of food prodced overseas with lower animal welfare standards.

It comes amid warnings from all sides about chlorinated chicken and hormone-injected beef making its way onto supermarket shelves in the UK.

The Government is expected to overturn the Lord's amendment in the Commons, and has consistently argued existing protections are already in place and they have no intention of watering them down.

Ms Thornberry said: “If it is (Ms Truss’s) argument that we don’t need Labour’s amendments because bans on relevant imports are already enshrined in law, can she please tell us which law prevents the import of pork that has been produced on American farms that continue to use sow stalls?”

Ms Truss said: "Well (Ms Thornberry) is of course talking about an animal welfare issue, and as I made very clear earlier on, we will not allow the high animal welfare standards of our pig producers to be undermined.”

Ms Thornberry countered: “There is no import ban against pork produced on farms using sow stalls because, as (Ms Truss) said, it’s an issue of animal welfare not one of food safety.

“That means, if the Government drops tariffs on US pork, British pork farmers will be undercut by cheap imports from American agricultural companies using practices that have been banned in our country for the last 21 years.

“So will the Secretary of State listen to reason and write into the law the protection of all UK farming standards against imports that don’t meet them?”

Ms Truss appeared to make a slip of the tongue when she replied: “In any trade deal we strike, we will be taking into account our high standards to make sure our farmers are undermined.”

She added: “If (Ms Thornberry) is suggesting a blanket ban on any foodstuffs that do not comply exactly with British farm regulations, what she is talking about is preventing developing countries sending their foodstuffs to the United Kingdom."

Alistair Carmichael, Lib Dem MP for Orkney and Shetland has urged the International trade secretary to meet farmers who are planning to protest outside Westminster on Monday over the protection of food standards.

Save British Farming will hold a demonstration in Parliament Square on Monday 12th October to voice concerns about the potential for trade concessions to the US to flood the UK market with cheap, low-quality food and undermine farmers and crofters. The protest comes on the same day that the Agriculture Bill returns to the House of Commons.

Mr Carmichael asked Ms Truss directly in thechamber today fi she would meet farmers on Monday, however Ms Truss said she had "met farmers from right across the United Kingdom" already.

The Lib Dem MP said after the exchange that the trade secretary was "not getting it".

He said: "The Secretary of State may say she has met farmers around the country but the message clearly is not sinking in. The fact that Save British Farming are holding a protest in front of Parliament next week should have been the clue.

“If the government is proud of our high food standards as they say then they should not be opening the floodgates to cut-corner products from the US. I will be proud to meet with the farmers from Save British Farming on Monday – and to back their calls for a fair deal for UK farmers and crofters in any trade agreement with the United States.”