The government has been accused of failing to prepare for Britains negotiations with the EU to collapse.
The Times uncovered a secret letter written by Chris Hopson, chief exec of NHS Providers, to Simon Stevens, chief of the NHS.
It reads: “In the event of a no deal or hard Brexit…the entire supply chain of pharmaceuticals could be adversely affected.
“Public health and disease control coordination could also suffer.
“And our efforts to reassure, retain and attract the European workforce on which the NHS relies could also be jeopardised.”
It adds that NHS England seems to "expect trusts to develop contingency plans individually, in a vacuum, and have to reinvent the wheel 229 times".
Hardcore Brexiteers have warned a second referendum could plunge the UK into anarchy.
Two years on from the historic EU referendum on June 2016, Britain is still sharply divided over the question of Europe – an issue that has plagued UK politics for decades.
SHOCK: The news comes from a secret letter from the chief of NHS Providers
The so-called Chequers agreement that she proposed in a white paper in July was not able to unite the Conservative Party around a consensus on the final deal.
Rather, her proposal led to the resignation of former EU-exit secretary David Davis and former foreign secretary Boris Johnson, who declared “Brexit dream is dying”.
Brexiteers such as Davis and Johnson want a clean break from the EU, but Mrs Mays plan seeks a “third way” that will tie Britain to a customs union for goods with the bloc.