A row has broken out after Labour leader Jeremy Corbyn claimed he had “proof” the NHS was at risk under a post-Brexit trade deal with the US.

Mr Corbyn said he had a 451-page dossier showing initial talks had taken place, proving the NHS was “for sale”.

But Prime Minister Boris Johnson said the claims were “nonsense” and the NHS would not be part of trade talks.

The Tory manifesto explicitly states neither the price paid for drugs nor NHS services will be “on the table”.

Meanwhile the SNP has published its manifesto which includes a pledge to “stop the NHS becoming a lever in any international trade deal” through its NHS Protection Act.

Mark Dayan, policy analyst and the head of public affairs at the Nuffield Trust think tank said the NHS was not being “flogged off” in the sense that US companies will not own hospitals.

But he said the documents suggest the US is trying various tactics to get the NHS to pay more money to their pharmaceutical companies for the drugs that they sell.

“Obviously from the NHS’s point of view, that is a concern… you’re really losing out in that situation,” he said.

Mr Dayan said if talks with the US continue, UK negotiators must “push hard for the interests of the UK and the NHS”.

What evidence has Labour obtained?

Labour obtained uncensored government documents covering six rounds of talks between US and UK officials in Washington and London between July 2017 and July 2019.

They are all preparatory meetings ahead of formal trade talks.

These documents provide more detail on the meetings Channel 4’s Dispatches programme reported on last month.

There is no indication in the documents that the UK team agreed to anything in the talks.

Jeremy Corbyn doesn’t provide evidence ministers have agreed the health service should be part of a trade deal with US.

But details of discussions about the demands of US pharmaceutical companies will still be motivating for Labour voters worried about the NHS.

“Not for sale,” has been the biggest mantra at Labour events, even though the Tories have always furiously denied the NHS is in any way “up for sale”.

It’s clear US drug companies want access to UK markets – Labour suggests the UK has agreed they could extend the patents on some medicines, which could cost the NHS more, for example.

The Conservative manifesto says the NHS will not be on the table in post-Brexit trade talks.

How the NHS keeps drug prices low

Currently, the NHS is able to use its bargaining power as a centralised health system to negotiate low prices for drugs.

It also has a strong track record in resisting attempts to lengthen patents on drugs, to allow cheaper generics to be used more quickly than they are in the US.

The US currently pays two and a half times more for drugs than the NHS does.

And Labour has warned this market could be extended further under the Tories.