Coronavirus: More than third of Wednesday's tests were postal kits, No 10 admits

Figures revealed days after statistics watchdog blasted health secretary Matt Hancock for 'misleading' presentation of testing numbers

More than a third of the 170,000 coronavirus tests claimed by the government on Wednesday were in fact kits sent out in the post, Downing Street has revealed.

The government was blasted by the UK's statistics watchdog earlier this week for "misleading" the public by including tests mailed to home addresses and NHS locations - which might never be used - in the tally announced at the daily Downing Street coronavirus briefing.

For the first time, No 10 today broke down the figures, revealing that out of 171,829 tests announced for the 24 hours to 9am on Wednesday, some 60,209 were sent out in the post.

The figures were released as the total number of tests conducted or posted out during the course of the pandemic passed 5 million, with a record 220,057 daily tally surpassing for the first time the 200,000 target set by Mr Johnson for the end of May.

In a scathing letter to health secretary Matt Hancock on Tuesday, UK Statistics Authority chair Sir David Norgrove said that the government’s presentation of testing figures “falls well short” of normal standards.

Lumping together home-testing kits with tests conducted in NHS labs and drive-through centres meant that the figures had “limited value” in helping the public and clinicians understand the progress of the outbreak, he said.

And he added: “The aim seems to be to show the largest possible number of tests, even at the expense of understanding.”

Sir David was also critical of the failure to give details of the numbers of people tested rather than the number of tests conducted. Many of those tested are swabbed more than once, with each counted as a separate test, potentially hugely inflating the final figure.

Boris Johnson's official spokesman told reporters that Wednesday's testing figure included 38,163 conducted in NHS, Public Health England and devolved administration labs, 34,526 at commercially-operated drive-through centres and mobile labs and 2,918 as part of an academic surveillance programme, while 60,209 involved kits mailed out to home addresses or NHS "satellite" centres away from the main labs. A further 36,013 antibody tests were conducted to see whether key workers had previously had the disease.

The total capacity for testing was 220,213, not all of which was used.

Testing for coronavirus is a vital part of the government's exit strategy from lockdown, as it allows the contacts of those known to have the disease to be identified and told to self-isolate for 14 days to avoid spreading the infection further. However, a significant number of home-testing kits are believed to have gone unused or to have been used incorrectly, reducing the total number of tests completed.

The PM's spokesman confirmed that almost half of a batch of 67,000 tests sent to the US for processing had to be retaken after being botched by a commercial lab.

Around 29,500 of the tests were returned "void", said the spokesman, who explained that tests were sometimes sent overseas for processing if there was not sufficient capacity in the UK at the time.

"Everyone affected was offered a new test immediately and the lab in the US has not been used for further surge capacity since," he said.