Some 400,000 surgical gowns ordered from Turkey have not been given to NHS workers because they do not meet British safety standards, the government has confirmed.
The shipment of personal protective equipment was flown to the UK by the RAF last month, but is now stuck in a government warehouse.
It is not clear if the government will seek a refund from the suppliers.
The Department of Health said it was working “night and day to source PPE”.
During the past few months as the UK has tackled the coronavirus pandemic, healthcare workers including doctors and nurses have complained of a lack of adequate kit such as gowns, masks and gloves.
PPE is essential for protecting front-line workers exposed to Covid-19, and without it workers are concerned they could catch or spread the virus.
Amid a row over the procurement of PPE in April, the government announced it had managed to source a large supply from Turkey.
After several delays, the RAF was deployed to fly it back to the RAF Brize Norton on 22 April.
But now the government has confirmed that all 400,000 surgical gowns that were delivered were unusable because they did not meet the required criteria.
The news was first reported by the Daily Telegraph.
In a statement, the Department of Health and Social Care said there were shortages of PPE around the world, not just in the UK.
“We are working night and day to source PPE internationally and domestically and brought together the NHS, industry and the armed forces to create a comprehensive PPE distribution network to deliver critical supplies to the frontline,” a spokesperson said.
“All deliveries of PPE are checked to ensure the equipment meets the safety and quality standards our frontline staff need. If equipment does not meet our specifications or pass our quality assurance processes it is not distributed to the front line.”
There are around 1.6 million NHS staff across the UK in hospitals and the community. All of them need varying amounts of PPE depending on the type of work they do.
Gowns have been one of the items of PPE which have seen shortages, with the chief executive of NHS Providers saying in mid-April that a significant number of health trusts had “critically low stocks”.