Mystery over why key scientists were dismissed from Boris Johnson’s press conference

Questions have been asked why Downing Street sent away England's chief medical officer (CMO) and chief scientific adviser (CSA) after they turned up to host the daily press briefing.

Both Chris Whitty (CMO) and Patrick Vallance (CSA) were expected to take questions from the media alongside prime minister Boris Johnson on Monday evening.

They were snapped arriving at Number 10 as senior adviser Dominic Cummings gave a briefing in the Rose Garden.

But they were seen leaving at approximately 6.20pm - shortly before the press conference.

Instead Public Health England medical director Yvonne Doyle fronted the event alongside the prime minister.

Joe Pike from Sky News tweeted: 'Earlier we were told they would be appearing with the PM at the daily press conference.

'Why did they turn up for the presser and then leave?'

On Sunday scientific advisers took to Twitter to complain that Johnson and Cummings had 'trashed' their lockdown work.

Professor Stephen Reicher, who sits on the Independent Scientific Pandemic Influenza Group on Behaviours (SPI-B) panel, wrote: 'I can say that in a few short minutes tonight, Boris Johnson has trashed all the advice we have given on how to build trust and secure adherence to the measures necessary to control Covid-19.'

Earlier Prof Reicher, who is professor of social psychology at the University of St Andrews, said: 'It feels increasingly as if we are living through a Greek drama.

'The kingmaker Cummings' fatal flaw of hubris brings down both him and the king… what makes it tragedy is that such incompetence and turmoil will bring the people down as well.'

In an interview on Sky News former Downing Street director of communications Alastair Campbell said that Whitty and Vallance should be asked if they knew where Cummings was while he was based in Durham.

He later tweeted: 'Is it too much to hope they refused to be part of a charade any longer?'

On Tuesday Downing Street said they did not take part in the press conference because the PM believed the questions would revolve around Cummings.

The official spokesman said: 'I think the view of the prime minister was that the questions yesterday were likely to be focused on the statement earlier in the day and would all be directed at him.

'And therefore that Patrick and Chris didn't need to take part. I think you can expect to see them at press conferences in the coming days. They were in No 10 yesterday in order to give an update to the PM, which they do regularly.'

Asked if they refused to express support for Cummings, the spokesman said: 'Nothing to suggest that, no.'