For the second day running, lateral flow tests are unavailable to be ordered via the Government website, though it is understood that a number were available in the early hours of the morning.
A message on the site on Tuesday morning said there were no tests available for home delivery, although tests can still be collected from pharmacies.
People attempting to order home testing kits from the UK Government were hit by problems yesterday.
On Monday, the UK Health Security Agency (UKHSA) said that “due to exceptionally high demand, ordering lateral flow tests on gov.uk has been temporarily suspended to fulfil existing orders”.
Ministers have insisted there is no issue over supply, but rather there are constraints on the delivery system for the tests, as they encouraged people to pick up testing kits from their local pharmacies.
However, many people have reported that their local pharmacy is out of stock.
Deputy Prime Minister Dominic Raab insisted the issue with ordering lateral flow tests from the Government website is not due to a lack of the tests.
He told BBC Breakfast: “The problem isn’t supply and volume, the problem is the allocation and distribution, or the delivery, of it.
“We know that in relation to the online system there were some challenges yesterday and that’s partly because of the proportion they’ve got each day.
“We’re making sure that however people may wish to order them and procure them, we’re ramping up not just the capacity … but the ability to distribute and to deliver.”
On Monday, Health Secretary Sajid Javid said limits on ordering tests are linked to delivery capacity, and said new arrangements have been reached with Amazon and others.
Mr Javid said: “There is no shortage of actual tests that are held by UKHSA. There are tens of millions of tests… the issue, the limiting factor because of the hugely increased demand… is the ability to deliver the tests and having enough capability to deliver the tests because the current arrangements with Royal Mail alone are not enough.
“There are new arrangements that I’ve reached with Amazon and other delivery methods.”
But Labour’s shadow health minister Wes Streeting described Covid testing as a “shambles”.
Mr Streeting said an increase in demand should have been foreseen, and added: “This is a serious problem. Those coming into contact with positive Omicron cases will not be able to follow the rules and get themselves tested on a daily basis.”
Nicola Sturgeon will announce whether further coronavirus restrictions will be imposed across Scotland in response to the growing outbreak of the Omicron variant.
The First Minister is due to make a statement at Holyrood on Tuesday setting out any new measures as well as updating the Scottish Parliament on the booster vaccination programme.
Scotland recorded 26 new cases of the Omicron variant on Monday, taking the overall number to 186, while a further 3,756 Covid-19 cases were confirmed.
Addressing MSPs last week, Ms Sturgeon stressed it was “important to keep the need for any additional protections under daily review” because of Omicron which “may be significantly more transmissible than anything before”.