Large US firms cannot be allowed to could flood Britain with low-quality food imports after Brexit, campaigners have warned after the Trump administration set out its demands for a trade deal.

The US wants 'comprehensive market access' for US agricultural products through the reduction or removal of tariffs and the elimination of 'unwarranted barriers' to food and drink imports according to a document released today.

Mr Trump's administration is also demanding full market access for US drug firms and a block on state institutions - such as the NHS - discriminating against American companies when purchasing goods and services.

The publication of negotiating objectives for a deal by the office of US trade representative Robert Lighthizer was welcomed by the Department for International Trade as a sign that Washington is keen to start talks soon after Brexit.

Securing a free trade deal with the United States is one of the UK's top priorities after Brexit, but the administration of Donald Trump, who made a memorable visit to Britain last year (above), are demanding a high price to do business

Liam Fox's department said the UK would insist on maintaining 'high standards for businesses, workers and consumers' in any deal.

But the National Farmers' Union raised concerns over food safety and animal welfare standards.

'It is imperative that any future trade deals, including a possible deal with the USA, do not allow the imports of food produced to lower standards than those required of British farmers,' NFU president Minette Batters said.

'British people value and demand the high standards of animal welfare, environmental protection and food safety that our own farmers adhere to.

'These world-leading standards must not be sacrificed in the pursuit of reaching rushed trade deals.'

US companies have long complained that EU regulations limit American exports of food products such as chlorine-washed chicken, hormone-boosted beef and genetically modified crops.

Mr Trump's commerce secretary Wilbur Ross warned in 2017 that continued adherence to EU standards after Brexit could act as a 'landmine' to UK hopes of a free trade deal with the States.

A Downing Street spokeswoman said: 'We have always been very clear that we will not lower our food standards as part of a future trading agreement.'

But Liberal Democrat MP Tim Farron, a supporter of the Best for Britain campaign for a new referendum, said: 'It's clear that the US ... wants to flood us with chlorine-washed chicken and hormone-pumped beef.

'But the British people won't be force-fed low-quality products or a bad Brexit deal. That's why we need a public vote.'

Labour MP Jo Stevens, a supporter of the People's Vote campaign for a second referendum, said the proposed deal - which also requires the removal of restrictions on transfers of personal data - would turn the NHS into 'a playpen for huge US corporate interests'.

'Donald Trump's administration has now made it clear just what it will be demanding from the UK in return for a trade deal - and one of those things is that we let big US companies run riot in the NHS,' said Ms Stevens.

The document published by US trade representative Robert Lighthizer was welcomed by the Department for International Trade but attacked by the National Farmers Union

Donld Trump's commerce secretary Wilbur Ross warned in 2017 that keeping EU food standards after Brexit could act as a 'landmine' to UK hopes of a free trade deal

Proposed measures would require that 'US drug companies - the very corporations that have caused the opioids crisis in their home countries through reckless marketing and pressure on doctors - get full access to the NHS', she warned.

Also sensitive for London are demands for the inclusion of currency matters in any agreement.

The paper states that the US wants Britain to 'avoid manipulating exchange rates in order to prevent effective balance of payments adjustment or to gain an unfair competitive advantage'.

And, in a move which could restrict British room for manoeuvre in future trade talks with countries such as China, Washington is demanding a mechanism allowing the US to 'take appropriate action' if the UK negotiates a free trade agreement with a 'non-market country'.

The document also states that a condition of any deal will be that the UK Government should 'discourage politically motivated actions to boycott, divest from, and sanction Israel'.

The negotiating objectives represent an opening gambit in what are expected to be lengthy negotiations stretching over a number of years.

Mr Lighthizer's office stressed the importance of the 230 billion US dollar (£173 billion) UK/US trade relationship.

But it added: 'Multiple tariff and non-tariff barriers have challenged US exporters in key sectors while the UK has been a member state of the EU and therefore a part of the common trade policy of the EU.

'The UK's decision to leave the EU creates a new opportunity to expand and deepen the US/UK trade relationship...

'Our aim in negotiations with the UK is to address both tariff and non-tariff barriers and to achieve fairer and deeper trade in a manner consistent with the objectives that Congress has set out.'

A spokesman for Dr Fox's Department for International Trade said: 'Negotiating an ambitious free trade agreement with the US that maintains our high standards for businesses, workers and consumers is a priority.

'So we welcome the US government publishing their objectives, which demonstrates their commitment to beginning talks as soon as possible.

'As part of our open and transparent approach to negotiations, we will publish our own negotiating objectives in due course.'