NUMBER 10's coronavirus briefings are "number theatre" that can't be trusted, an expert claims.

Earlier this week Professor Sir David Spiegelhalter, chair of the Winton Centre for Risk and Evidence Communication at Cambridge University, urged Prime Minister Boris Johnson not to cite his work on international Covid-19 comparisons.

Today he savaged the UK Government's daily briefings in a televised interview.

Appearing on The Andrew Marr Show, Spiegelhalter suggested the team putting the daily briefings together for the UK Government does not understand the figures on death tolls and case numbers.

The eminent statistician stated that it is "extraordinary" that it is not known how many people have had Covid-19.

And he branded Saturday's session "completely embarrassing".

He said: "We get told lots of big numbers, precise numbers of tests being done - 96,878. Well, that's not how many were done yesterday, it includes tests that were posted out.

"We're told 31,587 people have died. No they haven't, it's far more than that.

"I think this is actually not the trustworthy communication of statistics.

"It's such a missed opportunity. The public out there who are broadly very supportive of the measures, they're hungry for details, for facts, for genuine information, and yet they get fed this what I call 'number theatre', which seems to be co-ordinated really much more by a Number 10 communications team rather than genuinely trying to inform people about what's going on.

"I just wish the data was being brought together and presented by people who really knew its strengths and limitations and could treat the audience with some respect."

READ MORE: Statistician tells Boris Johnson to stop citing his coronavirus article

Spiegelhalter also raised concerns about a lack of information on how many people have had the virus.

He told the programme that some say the infection fatality rate - the proportion of people infected with the virus who go on to die - is around 1%. Putting the number of deaths at around 35,000 deaths, if this is multiplied up, it would mean that around 3.5 million people have been infected.

But others put the infection fatality rate at a different percentage, with some saying the infection fatality rate is half of one percent, which would mean that seven million have been infected, while others claim half the country has been infected, he said.

When asked how scared the public should be about Covid-19, Spiegelhalter said: "I'm not saying how anybody should feel, or what they should be worried about, but my aim, as a statistician, was that people's anxiety should be at least roughly proportional to the actual risks that they face."

On the instruction to the PM, he said his article was not suggesting that no international comparisons should be made, but issuing a warning about how this is done.

He said: "I felt forced, and my colleagues encouraged me, to go public and say 'Please don't do this, it's not what I meant, don't use this to make this claim that we can't make comparisons'."