The Prime Minister will provide a statement to the nation tonight after the UK's Covid alert level was raised.
Boris Johnson is expected to give a televised Covid update at 8pm from Downing Street after the UK Covid Alert Level was increased from Level 3 to Level 4.
The four UK chief medical officers said in a joint statement that the increase comes "in light of the rapid increase in Omicron cases", the Mirror reports.
READ MORE: Live Updates as Boris Johnson set to make Covid statement
A statement said: "Early evidence shows that Omicron is spreading much faster than Delta and that vaccine protection against symptomatic disease from Omicron is reduced.
"Data on severity will become clearer over the coming weeks but hospitalisations from Omicron are already occurring and these are likely to increase rapidly."
The UK Health Security Agency said a further 1,239 confirmed cases of the Omicron variant of coronavirus have been recorded in the UK as of Sunday.
It brings the total number of UK cases of Omicron to 3,137, a 65 per cent increase from Saturday’s total of 1,898 UK cases.
Mr Johnson is also expected to speak on ramping up the booster rollout.
The statement continued: "The NHS is currently under pressure mainly driven by non-COVID pressures. With a variant spreading with increased transmissibility and reduced vaccine effectiveness, we are likely to see this pressure rise soon.
"It is extremely important that if you are eligible, you get your Covid vaccination now – whether this be your first, second or booster dose.
"People should continue to take sensible precautions including ventilating rooms, using face coverings, testing regularly and isolating when symptomatic."
