Jeremy Hunt has admitted that British patients may find it difficult to get EU cancer drugs if Brexit talks break down, describing the risk as “uniquely damaging”.

The Health Secretary was being pushed for details of his department’s preparations for the event of a “no deal” scenario, which could cause major disruption to the supply of life-saving medications and see more pharmaceuticals companies shift operations to the EU.

Drug giants have told of “significant disruption to the supply chain for medicines” and that customs delays would damage “time and temperature sensitive” materials, without a Brexit deal.

“It is uniquely damaging to both parties if we don’t come to an agreement,” Mr Hunt told an inquiry by the Commons Health Committee.

“It’s not just that want to continue to get cancer drugs that are manufactured in Europe. It’s Europeans who will not want any interruption to their supply chain for drugs that are manufactured in this country.”

Mr Hunt said it was the issue’s importance that gave him “a lot of confidence that we will be able to agree what we need to agree”.

The admission came as the Health Secretary threw doubt on Theresa May’s hopes of striking a transition deal to cushion the impact of EU withdrawal before April, warning it “may take a little bit longer”.

The stance will alarm business leaders, who have warned they will be forced to implement plans to shift part of their operations out of the UK without an agreement by the end of March.

This week, the Confederation of British Industry’s director general, Carolyn Fairbairn, pleaded with Theresa May to speed up the talks in order to deliver a transition deal within 70 days.

Companies badly needed clarity that the Brexit talks were not heading for the rocks, or they would begin to move jobs and investment offshore, she said.

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Failing to secure a deal would be an act of “great economic self-harm”, imposing billions of pounds of costs on UK goods sold to and bought from the EU, Ms Fairbairn added.

At the Health Committee hearing, Conservative MP Andrew Selous warned against any delay, telling Mr Hunt: “Weeks are critical at the moment.”

Mr Hunt added that UK companies with concerns about licensing drugs in the EU should consider opening a European office, to make European Medicines Agency approval easier.

Last year, Britain’s biggest drugmaker said it would have to divert up to £70m from developing new cancer drugs in order to prepare for the possible harsh impact of Brexit.

GlaxoSmithKline estimated that 1,700 of its products would be directly affected by the need for new regulation processes and approval systems – leaving less money for clinical trials.

Because of the threat, the Government is believed to be considering an attempt to stay under EU regulation, as it is for the chemicals and aviation industries.

Such a move would be welcomed by the pharmaceutical industry, but would be a headache for Theresa May if it crosses her “red line” that the European Court of Justice must play no role in settling disputes.