People meeting friends and family this Christmas have been issued an urgent warning over taking lateral flow tests.
Boris Johnson has urged caution over the Omicron variant and has promised to keep the data under constant review.
New restrictions are unlikely to stop family and friends celebrating Christmas together but speculation grows that further measures will be needed to curb the variant's spread.
READ MORE: Boris Johnson's next announcement date as PM 'considers banning indoor mixing'
Some experts had warned people should have avoided meeting others this week if they wanted a 'good Christmas dinner'.
Stephen Reicher, professor of psychology at the University of St Andrews and a member of government advisory body the Scientific Pandemic Insights Group, said we probably need more restrictions “but that needs to go along with adequate support for business and individuals”.
He warned that the first thing people should do who are meeting up is to take a lateral flow test to 'stack the odds' in their favour.
“They’re not perfect but, if we take them, they improve our odds. Make sure that the spaces we go into are as well ventilated as possible, that we think about distancing, meet outdoors if we can.
“We can do all sort of things to stack the odds in our favour but the bottom line is the more we meet before Christmas, the more we put Christmas at risk.”
However, experts have warned that people should take the lateral flow just before they meet up with others due to the apparent infectiousness of the Omicron variant.
Irene Petersen, a professor of epidemiology at University College London, said official advice should be updated as those infected with Omicron “may switch from being non-infectious to infectious within hours”.
Government guidance currently recommends taking a test “if you will be in a high-risk situation that day”.
Prof Petersen told The Sunday Telegraph: “That’s not good enough. We’re seeing so many examples now where people have taken a test a day before and then when they take one the day after they are positive.
“Omicron is very, very fast, so the test result expires very quickly. It is hours that we are talking about now.”
According to the Mirror, insiders at Whitehall claim the PM is weighing up a return to Step 2 restrictions in England.
This would lead to a ban on indoor mixing and a return to hospitality venues being forced to serve customers outside.
According to the Sunday Times, Boxing Day has been pencilled in for an announcement with measures possibly starting as early as December 27.
