The US expressed a preference for a no-deal Brexit in meetings with UK officials, the Labour party has said.

Jeremy Corbyn reveals dossier 'proving NHS up for sale' Read more

Speaking at a press conference on Wednesday, the Labour leader said that official documents from preparatory trade meetings between the UK and US revealed that the future of the NHS was at risk.

The Conservative party accused Corbyn of indulging in conspiracy theories, with Boris Johnson giving “a cast-iron” guarantee that the NHS would not be on the table in post-Brexit trade talks.

As well as highlighting evidence that the US was keen to discuss the issue of drugs pricing and obtain “full access” to UK markets, Corbyn pointed to a passage in one of the documents that said: “there would be all to play for in a no-deal situation”.

The document details a meeting on 10 and 11 July this year of the UK-US Trade and Investment Working Group, which was designed to lay the groundwork for a potential future trade agreement once the UK leaves the EU.

It was held before Boris Johnson was elected as Conservative party leader and was forced to ask for an extension to the UK’s EU membership at the end of October.

“UTTR [US trade representatives] were also clear that the UK-EU situation would be determinative: there would be all to play for in a no-deal situation but UK commitment to the customs union and single market would make a UK-US FTA [free trade agreement] a non-starter,” the document reads.

“We will play the sequencing of the next full working group by ear but have agreed a work programme for the next two months for coordination teams to take forward discussions on structure, sequencing and ways of working.”

A Conservative party source said that it was simply fact that it would not be possible to do a free trade deal with the US if the UK remained in the single market and customs union.

Corbyn said: “What’s at stake in a deal with Trump could not be more important for our country. In this election the Conservatives want you to vote blind, keeping millions of us in the dark about their plans.”

The document also notes the pressure from “political leadership” to ensure that both countries were prepared for negotiations to start as soon as the UK left the EU, with rounds of meetings every six weeks. “He felt that being able to point to advanced negotiations with the UK was viewed as having political advantages for the president going in to the 2020 elections,” it said.