I heard someone comment recently that the UKgov seemsto be incresing the "targets" to give the impression they have reached previous targets, so they'll say they want to do 10 000 tests, then announce the new 'target' is 20 000, and a week later say they are aiming for 100 000...
They are still barely at the 10 000 mark three weeks later, but it gives the impression it's increasing rapidly, so people assume they are testing a lot more people than they actually are.
If that's happening then this could be more of the same.
Some of the extra capacity in testing Matt says is down to NHS staff not taking up offer of being tested.