The NHS has declared a national emergency over shortage of feed for babies and disabled patients, with some patients being told to go to Accident & Emergency departments.

Medics said vulnerable patients were being left starving for several days, with some being admitted to hospital because of malnutrition.

Hundreds of NHS patients, including children, who depend on intravenous nutrition, have been experiencing delays in deliveries.

It follows an inspection by watchdogs which found manufacturers were failing to meet safety standards, and the presence of potentially fatal bacteria.

The NHS national patient safety director Dr Aiden Fowler has written to all NHS hospital trusts, and affected patients, warning that the incident has been designated as an emergency incident, under the Civil Continencies Act, at the highest level.

British manufacturer Calea had already said the shortages could last up to four weeks.

But the letter warns that the crisis could last far longer, outlining plans to ration the product to those most in need.

The feed, which is used by vulnerable and disabled patients, in hospital and their own homes.

Parents said the situation was “terrifying” with some told to go to A&E if vulnerable chidlren were left too long without being fed.