The government has failed to hit its 100,000 tests a day target for the third day in a row.
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 since then the government has failed to hit the target figure.
Some 84,806 tests were carried out on Monday.

Just 85,186 tests were provided on Sunday and only 76,496 on Saturday - a day after the government met its target.
While thousands of those will have been at-home tests, which are counted as they are dispatched by courier, rather than when the test is actually performed.
Health Secretary Matt Hancock said on Monday the UK's capacity for testing yesterday was 108,000.

Ministers insist testing capacity remains high, but put the lower figures down to fewer people being at work at the weekend.
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Stephen Powis, National Medical Director of NHS England, said: “We are now at a very high level of testing - over 100,000 - a little bit of a dip over the weekend.
“But we anticipate that that testing capacity will continue to increase and it's a very important component of our approach going forward.”