The Government has missed its target for Coronavirus testing for the fifth day in a row.
New figures show 86,583 tests were provided in the 24 hours to 9am on Wednesday - an increase of around 17,000 on the day before, but still dramatically below the 100,000 a day target.
It comes after Downing Street blamed yesterday's dramatic drop in tests provided on "technical issues" in a single lab.
Just 69,463 tests were conducted, well below the 100,000 daily target, although there was capacity to carry out 100,454.
The Prime Minister's official spokesman said: "Yesterday's figures reflect some particular technical issues which affected the number of samples which were processed over the proceeding 24 hours.
"These were issues which arose in a single lab. We've worked to resolve them and capacity is being rapidly restored."
Tests have repeatedly failed to meet the 100,000 target since it was achieved at the end of April.
The spokesman said: "The target was 100,000 tests at the end of April. The purpose of the target was to drive up capacity in order that we could provide a test for anyone who needed one."
Yesterday Boris Johnson shocked PMQs viewers by promising to double the goal to 200,000 by the end of May.
Matt Hancock promised the UK would get to 100,000 tests a day by the end of April.
Ministers claimed victory on passing the 100,000 a day target on Friday, despite counting tens of thousands of tests which had only sent out by courier, not analysed by labs.
But the government only managed to hit that on two days, Friday and Saturday.
On Sunday ministers insisted testing capacity remains high, but put the lower figures down to fewer people being at work at the weekend.
It was revealed on Friday that tens of thousands of at home tests a day are counted towards the daily figure when they are sent out by courier - rather than when they are processed by a lab.
Ministers claimed victory on passing Health Secretary Matt Hancock’s target on Friday, despite counting tens of thousands of tests which had only sent out by courier, not analysed by labs.
Meanwhile, a row over testing in Wales has reignited after a senior health official claimed the UK Government scuppered a deal with a pharmaceutical giant to provide 5,000 tests a day.
Tracey Cooper, chief executive of Public Health Wales, told the Senedd's health committee there had been discussions with Roche for 5,000 tests a day for Wales.
But then it was "brought into the UK allocation" and Wales was left with just 900 a day, the committee was told.
On April 1, First Minister Mark Drakeford told a session of the plenary that Roche should have "honoured" the agreement for 5,000 tests a day.
Public Health England said it "did not intervene in any discussions" between Roche and Wales, while the Swiss firm said it "never had a contract or agreement directly with Wales to supply testing" for Covid-19.
"We were in the discussions with Roche and that was the understanding we had through discussions and email correspondence," Dr Cooper told the committee.
"And that was in advance of it then being, as I say, brought into the UK allocation, which has happened with a couple of companies."
Plaid Cymru's health spokesman Rhun ap Iorwerth asked Dr Cooper: "So in a way, Welsh Government has done well in going early with Roche.
"They said they could deliver 5,000, then the UK Government stepped in and we lost that 5,000?"
Dr Cooper replied: "Yes, and I think what the UK Government... the allocation at the time was for the full 5,000 for the UK.
"So it's challenging for ourselves, challenging for the UK. But the allocation that we're getting now is more than we would on a relative population basis."
She told the committee Wales is receiving 19% of Roche's UK allocation - around 900 tests a day.
Dr Cooper also said she was not "not familiar" with Welsh ministers' original aim to carry out 9,000 daily tests by the end of April.
Health Minister Vaughan Gething said on March 21 that Public Health Wales was aiming for capacity for 9,000 tests by the end of April. The target was subsequently reduced to 5,000 a day and then scrapped.
Questioned by Mr ap Iorwerth about the target, Dr Cooper said: "I'm afraid I am not familiar with the 9,000 number you refer to.
"We have worked very closely on a daily basis looking at what our trajectory is going to be. A month ago we were 1,000 tests a day, a fortnight ago we were 1,800 tests a day, and today we are 2,350."
Conservative health spokeswoman Angela Burns accused the three representatives of Public Health Wales who were giving evidence to the committee - Dr Cooper, Quentin Sandifer and Giri Shankar - of "evading" the question about the 9,000 target.
"I am genuinely shocked that Public Health Wales is saying on the record publicly they were not aware of the Welsh Government's commitment, which was said very clearly and loudly that there was an ambition for 9,000 a day testing capacity by the end of April," Mrs Burns said.
Addressing Dr Cooper, she added: "I am shocked. You are the chief executive of Public Health Wales and that is a major, major Government commitment."
