The testing total was 84,806 up to 9am on Tuesday, 85,186 up to 9am on Monday and 76,496 up to 9am on Sunday.
Shadow health secretary Jonathan Ashworth said: “One hundred thousand completed tests a day was pledged. Instead testing has gone down for the fourth day in a row.
Opposition leaders have demanded an explanation for the decline in coronavirus testing, after the British Government missed its 100,000-a-day target for the fourth day in a row.
UK Labour said that the news “does not inspire confidence” in plans to begin easing the UK lockdown, which are expected to be announced on Sunday.
A total of 69,463 tests were conducted in the 24 hours to 9am on Wednesday, according to Housing Secretary Robert Jenrick.
Testing should be going up, not be on this downward trajectory. Ministers need to explain why they are failing to deliver the testing promised.”
Boris Johnson marked his return to the Commons by setting a new ambition for increasing test capacity to 200,000 a day by the end of the month.
But Labour leader Keir Starmer pressed the prime minister on why current capacity had not been fully utilised since the end of April.
“On April 30, the Government claimed success in meeting its 100,000 tests-a-day target. Since then, as the Prime Minister knows, the number has fallen back,” he said.
“On Monday, there were just 84,000 tests and that meant 24,000 available tests were not used.
“What does the Prime Minister think was so special about April 30 that meant that testing that day was so high?”
Deputy leader Angela Rayner added that the “consistent downward trend” was “really not good enough”.
“It doesn’t inspire confidence to start easing lockdown,” she wrote on Twitter.
It comes as Health Secretary Matt Hancock claimed the UK is now a world leader in testing for Covid-19, though he conceded that capacity for checks had needed to be built up “almost from scratch” since the start of the outbreak.
Mr Hancock admitted that it would have been “wonderful” to have a diagnostics industry like Germany to tackle the coronavirus crisis, but insisted the UK has now caught up with the Germans in terms of testing.
Appearing on Sky News on Wednesday, Mr Hancock acknowledged that a lack of capacity meant it had not been possible to test everyone leaving hospital before they went into a care home.
When asked whether these tests should have been introduced earlier, he said: “The problem was that the testing didn’t exist and we had to build that testing capacity.”
The Health Secretary said ministers had put “a huge amount of effort and resources” into supporting care homes during the pandemic.
But he added: “It would have been wonderful if we had gone into this crisis with a global-scale diagnostics industry, in the way that Germany did.
“But we went in more like other countries like France, which similarly have had to build testing capability almost from scratch.”
Mr Hancock claimed that Britain is “miles ahead” and now a world leader when it came to testing for the virus.
“We invented the test in January. In February we got the number of tests up to 2,000 (a day). In March we multiplied that by five times to 10,000. Then we set the 100,000 target,” he told Sky News.
“The Germans started with this enormous diagnostics industry. But if you look at other countries around the world we are miles ahead on testing and we are now one of the world leaders.
“It is true that Germany has a very high capacity – about the same as ours. So we have basically caught up with Germany that started with this massive capability.
“We are miles ahead of South Korea now. Absolutely.”
England’s chief scientific adviser, Sir Patrick Vallance, told MPs on the Health and Social Care Committee on Tuesday that it would have been “beneficial” if testing capacity had been ramped up more quickly.
“I think that probably we, in the early phases, and I’ve said this before, I think if we’d managed to ramp up testing capacity quicker it would have been beneficial,” he said.
At the same committee, England’s deputy chief medical officer, Dr Jenny Harries, said limited resources meant a balance had to be struck at the time.
But she added that “if we had unlimited capacity, and the ongoing support beyond that, then we perhaps would choose a slightly different approach”.