American health companies believe the UK market will be easier to crack after Brexit, documents revealed in the Mirror show.
US pharmaceutical giants are keen to raise prices and charge the NHS more for life-saving drugs.
A document written by the US Chamber of Commerce and Coalition of Services Industries reveals that they are waiting to take advantage of a vulnerable UK post-Brexit.
The 24-page document, entitled Services Priorities for a Future US-UK Trade Agreement, reads: "Negotiations between the United States and the UK may encounter some of the difficulties that arose during TTIP.
"Concerns about potential impacts on Britain's National Health Service are being aired. It should prove easier to overcome these challenges with the UK as an individual negotiating partner."
Shadow Health Secretary Jonathan Ashworth said: "Today's revelations are yet more evidence that US big pharma companies are lining up to cash-in on a toxic Johnson-Trump deal.
"These mega corporations want us to pay more for medicine and the proposed US-UK deal could draw £500million a week from our NHS."