The firm told the newspaper more than two million tests were delivered on Christmas Eve to support pharmacies that remained open over the Christmas Bank Holiday.

“We continue to distribute around 2 million lateral flow tests daily from stock made available to us from UKHSA,” the spokesman said.

People struggling to get lateral flow tests “should just refresh” their webpage, the Education Secretary said on Monday, as some people still reported issues with accessing the kits.

Nadhim Zahawi told Sky News he had organised a separate supply of tests for schools ahead of children’s return to the classrooms.

A source in the testing industry told The Telegraph the UK had “burnt through” its stocks of rapid lateral flow tests before Christmas as demand for the kits surged.

The tests would usually be shipped into the country from abroad, before being stored in UKHSA warehouses and then distributed to pharmacies, the source claimed.

‘We’ve all gone lateral flow mad’

But the source said last week stocks were going directly to distributors, bypassing the warehouses, “which just tends to suggest the original stocks that ministers were claiming they had, well I’m sure they did have it, but we’ve burned through it”.

“We’ve all gone lateral flow mad,” the source added.