As it happened: More Covid records will be broken, warns Whitty - BBC News
England's chief medical officer says that the Omicron variant is moving at an "absolutely phenomenal pace".
There have been estimates around today that one million people will be isolating with positive Covid tests on 25 December.

But how is that figure calculated? We'll take you through it.

We know that on Tuesday there were about 60,000 positive cases reported in the UK.

Not all of those will have been tested in a way that gives an indication of whether they had the Omicron variant, but we know from the latest figures for England that of the tests that could give that indication, 24% were suspected of being Omicron.

So we can estimate that about 14,000 people testing positive in the UK yesterday had the new variant.

The government says that Omicron cases are doubling every two to three days.

With a three-day doubling, that would give us 28,000 new cases on Friday, 56,000 next Monday, and 112,000 on the 23rd.

Add up all those people who would still be in isolation by Christmas Day and you get to about 600,000.

If you assume that cases of the Delta variant stay completely stable between now and Christmas that is enough to get you to one million.

Alternatively, if Omicron cases are doubling every two days then you get to one million without any Delta cases at all.