At a press conference on Wednesday morning Jeremy Corbyn announced Labour had accessed a 451 page dossier detailing ongoing negotiations between the United States and UK regarding a post-Brexit trade agreement. The documents themselves disclose the minutes from several separate meetings of the UK-US trade and investment working group. They are relevant because they reveal the nature of negotiations between the two countries from early 2017 to early 2019. During this period Boris Johnson was foreign secretary.

There are two explosive revelations that immediately stood out.

The first is that the United States sees a no deal Brexit – still possible if Britain fails to reach an agreement with the EU by December 2020 (or indeed after in the likely event of an extension) – as most conducive to agreeing an extensive free trade agreement. As one civil servant writes in the minutes:

“USTR (United States Trade Representative) 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-U.S. FTA a non-starter.”

There is both a statement of fact here, and an important inference. The statement of fact is Britain won’t have a free trade deal with the United States if it remains in a customs union with the EU. Labour policy is that a customs union will be included in any leave deal negotiated and put back to the people in a second referendum. The important inference is that the United States views no deal – which they clearly regard as highly possible – as the best basis on which to agree a comprehensive free trade agreement.

Why? Because in the absence of a deal with its largest trading partner, Britain will be vulnerable and exposed. This would mean the United States would have even greater leverage in negotiations. The idea that the NHS and healthcare would remain immune in such a context is painfully naive. Indeed in their own manifesto the Tories write, “we should open up trade in services”. The document stating “there would be all to play for” merely repeats what Donald Trump said on the issue earlier this year. When asked if the NHS would be on the table in a trade deal in June he replied “everything would be on the table… NHS or anything else”. What this document makes clear, which we didn’t know already, is that the United States sees no deal as the best way to reach the ‘comprehensive’ trade agreement that Trump wants.

The second revelation is that the White House views the spectacle of ongoing negotiations in 2020 as politically expedient in Trump’s bid for re-election. As one document states:

“…my opposite number (the USTR) thought that there would remain a political and resource commitment to a UK negotiation even if it were thought that the chances of completing negotiations in a Trump first term were low. 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.”

If such an advantage is perceived to exist by the White House, then surely it would want them to continue over the course of the 2020 election campaign? What is more, the admission of the chances of any deal being struck in Trump’s first term being low – given that would be by the end of 2020 – is also an admission that any transition arrangement with the EU (or what Johnson calls ‘getting Brexit done’) would also have to be extended.

To be clear: the transition arrangement would kick in once a deal was agreed for Britain’s withdrawal from the EU – which could be as soon as January 2020 if Johnson wins a majority next month. After that Britain would no longer be a member of the EU but would still be subject to its rules. The hope is that this would last only until December 2020, by which time Britain would be ready to implement new trading relationships not only with the EU but others like the US. But as the above makes clear neither the Americans, nor the British, see this as likely. Indeed given America’s last major trade deal, with South Korea, took six years to negotiate, it is entirely possible that the ‘transition arrangement’ would last just as long. During this time Britain would be pulled in separate directions – one would be a customs deal with our biggest partner, the EU, the other would be a free trade deal with America, the condition of which would be a break on things like shared standards with Europe. At best negotiations with America would be ‘advanced’ just as the transition arrangement is meant to end. We will not be leaving it when the Tories say we will.

The dossier is a game-changer and shows many things, including a focus between the two on enhancing patent law around pharmaceutical drugs – which would only make them more expensive. But most importantly they reveal what Johnson’s offer to ‘get Brexit done’ really means: a decade of Britain being pulled in multiple directions and vulnerable to being pillaged by Trump’s America.

Most importantly it shows what the United States really wants: no deal. So too, it appears, does Johnson – for no other reason than a US trade agreement appears close to impossible without it. Corbyn has called the dossier more evidence of a ‘plot against our country’. He’s right.

Aaron Bastani is a Novara Media co-founder and contributing editor. For more from Aaron, sign up to his newsletter here.