Supplies of medicine should be deemed more important than shipments of food if there is a no-deal Brexit, the health secretary has told MPs.

Matt Hancock made clear his view when answering questions at the health and social care select committee. “The thing is that medicines will be prioritised in the event of a no-deal Brexit,” the health and social care secretary said when asked by the former Labour health minister Ben Bradshaw which would be given precedence.

Bradshaw responded: “Over food? Over vital food?”

Hancock replied: “Of course medicines will be prioritised. And we have been through detailed, line-by-line analysis of the 12,000 licensed medicines in the UK. In fact we had our latest meeting on it this morning, the three of us were there, in order to ensure there is a plan for the continuity for all medicines in the event of a no-deal Brexit.”

Britain gets far more of its pharmaceuticals from or via the EU than it does food, said Hancock. About half of all the drugs that the NHS uses are imported from or “have some touchpoint with the EU”, he added.

The growing prospect of Britain leaving the UK on 29 March without a deal means that NHS contingency plans have been activated, “covering logistics arrangements for both clinical and non-clinical supplies”, the NHS England chief executive, Simon Stevens, told the hearing.

But he stressed that the health service was “completely reliant” on the transport infrastructure to ensure that supplies of drugs and medical devices were not disrupted if there is no deal.

Matt Hancock: ‘We have been through detailed, line-by-line analysis of the 12,000 licensed medicines in the UK.’ Photograph: POOL New/Reuters

The shadow health secretary, Jonathan Ashworth, said: “The fact that the health secretary is forced to make decisions over whether to prioritise medicine over food in the event of a Tory no-deal Brexit is simply astonishing.

“And it’s all the more irresponsible that Theresa May stubbornly refuses to rule out no deal. Playing Russian roulette with the national interest and putting peoples’ health at risk like this is shameful and scandalous.”

Stevens also confirmed that the longstanding NHS target to treat A&E patients within four hours is to go. Under new access standards, those with minor ailments will have to wait longer.

New clinical targets would be introduced next year on a trial basis and adopted across England if they proved effective, he said.

But the Royal College of Emergency Medicine, which represents A&E doctors, condemned the move as “reckless” and warned that patients’ health would suffer as a result.

“It would be reckless if we do it without an evidence base and at the moment there’s no evidence that dismantling the four-hour standard would be good for patients. It would be the opposite, based on good clinical evidence,” said Dr Taj Hassan, the college’s president.

“Emergency departments will become more crowded. They will also become more intense for staff to work in. And it will lead to quantifiable harm among patients.

“There’s a lot of evidence that delays in assessments and delays in treatment lead to greater mortality.”