Concerns have been raised that updated government guidance on personal protective equipment (PPE) could put hospital staff and patients at risk.
Healthcare workers have been advised to reuse gowns or wear different kit, such as plastic aprons with coveralls, if stocks in England run low.
Unions representing doctors and nurses have expressed concerns about the updated Public Health England guidance.
The government said it is working to provide the PPE stocks hospitals need.
There have been warnings some hospitals could run out of the gowns used in intensive care units this weekend.
Healthcare staff treating patients with Covid-19 have previously been advised to wear long-sleeved disposable fluid-repellent gowns.
But Public Health England changed its guidance on Friday, outlining three options if the gowns are not available as “some compromise is needed to optimise the supply of PPE in times of extreme shortages”.