Amazon will deliver coronavirus tests to people’s homes as the government scrambles to deliver its promise of 100,000 per day.
Number 10 admitted it was still performing fewer than half as many tests as it had capacity for.
Most testing is currently being carried out in drive-through testing facilities - leaving many NHS and care workers unable to use them because they don’t have access to cars.
The number of drive-through testing facilities is set to almost double in the next week - and each will have a ‘mobile’ testing facility.
The PM's spokesman admitted there was "a great deal more to do if we're going to make full use of the capacity we have."
Number 10 said the UK has capacity to perform 48,273 tests a day.
But only 22,814 tests were performed in the 24 hours to 9am on Wednesday.
Some 28 drive-through testing sites are currently open, and Number 10 says that will increase to 50 in the next week.
The mobile units will visit care homes to test residents and staff.
Currently four mobile facilities are in operation. - operating in Salford, the Isle of Wight and Teesside.
But the intention is for a mobile unit to work out of all 50 testing sites by the end of the month.
Separately, tests will be sent out through Amazon to people's homes.
The Prime Minister's official spokesman said: "The number of people we've tested has increased in the most recent 24 hours we've got figures for and the gap between the number of people tested and the number of people we've tested has closed slightly.
"But that doesn't distract from the fact that there's a great deal more to do if we're to be able to say we're making the full use of the capacity we have."
