TWO senior UK Government advisers were seen leaving Downing Street before the daily coronavirus briefing.

The media were told Chief Medical Officer, Professor Chris Whitty, and Chief Scientific Adviser, Sir Patrick Vallance, would be appearing with Boris Johnson at the conference. 

But they were seen leaving No 10 at 6.20pm, 40 minutes before the briefing started. 

They were replaced by Dr Yvonne Doyle, director of health protection for Public Health England.

Joe Pike, Sky News political correspondent, alerted his Twitter followers to the incident.

He said: "NEW: Prof Chris Whitty and Sir Patrick Vallance left No 10 at approx 1820.

"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? Have asked No 10 for comment."

A Downing Street spokesperson told Pike that as the questions from the public and the media would be about the main political topic of the day, it was not necessary for Vallance and Whitty to be present.

At the briefing, Johnson said Cummings has not "undermined" lockdown messaging.

He stressed that he did not believe that his any of his staff in Downing Street had done anything to undermine the lockdown messaging.

He added: “I cannot give unconditional backing to anybody, but I do not believe anybody in Number 10 has done anything to undermine our messaging.”

READ MORE: PM says Dominic Cummings' trip does not undermine lockdown messaging