Questions have been raised over Sir Patrick Vallance's absence from last night's Downing Street briefing.
The Chief Scientific Adviser, alongside Chief Medical Officer Chris Whitty, is usually part of the line-up for major No10 press conferences held by Boris Johnson.
But his no-show did not go unnoticed, with some speculating on social media whether he did not agree with the messages being communicated.
One wrote: 'Johnson was pretending to know/care about anything other than keeping to his damn roadmap and Whitty looked like he was pretending to agree with him. Valance sensible enough to be absent.'
Another added: 'Where is Vallance? What was his advice?'
However, Sir Patrick's department, the Government Office for Science, told MailOnline the Chief Scientific Adviser 'does not attend every press conference'.
A spokesperson added that 'a range of medical and scientific advisors join the Downing Street Coronavirus press conferences', and that on this occasion, it was just Professor Whitty alongside the Prime Minister.
Chris Whitty and Boris Johnson were not joined by Patrick Vallance last night, with many questioning his absence
The Chief Scientific Adviser is usually part of the line-up for major No10 press conferences
Mr Johnson used the briefing last night to warn that plans to end lockdown restrictions next month are in jeopardy as scientists feared the Indian coronavirus variant could be 50% more transmissible than the Kent strain.
The Prime Minister told a Downing Street press conference that England will face 'hard choices' if the Indian variant of concern turned out to be much more transmissible than others.
Professor Whitty said that would mean 'a really significant surge' in infections, as he predicted the variant could become the most dominant strain across the UK.
Mr Johnson said he will press ahead with plans to lift restrictions on Monday, permitting people to mix indoors as well as allowing physical contact to return between households for the first time in over a year.
In a bid to dampen the effects of the variant, Mr Johnson announced that people aged over 50 and the clinically vulnerable will have their second doses of a Covid vaccine accelerated.
The downbeat briefing took place as it emerged the Scientific Advisory Group for Emergences (Sage) concluded it is 'highly likely' the Indian strain is more transmissible than the one that emerged in Kent.
The minutes of the meeting on Thursday showed they believe there is a 'realistic possibility that it is as much as 50% more transmissible'.
They warned there will be an even faster increase in cases if restrictions are lifted, suggesting a peak of infection can be expected after Monday's easing, and certainly at step four in June when all legal limits on social contact are due to end.
Sage said that if higher levels of transmissibility are confirmed, moving to step three on Monday could 'lead to a substantial resurgence of hospitalisations (similar to, or larger than, previous peaks)'.
The scientists also acknowledged there 'may be some reduction in protection' conferred by vaccines on the Indian variant.
During the Downing Street briefing, the Prime Minister said: 'I do not believe that we need, on the present evidence, to delay our road map and we will proceed with our plan to move to step three in England from Monday.
'But I have to level with you that this new variant could pose a serious disruption to our progress and could make it more difficult to move to step four in June.'