Boris Johnson has warned of a “tidal wave” of Omicron ready to hit the UK that could “cause many deaths”.
In a pre-recorded address to the nation on Sunday evening the Prime Minister also confirmed that extra support would be made available to assist in the booster roll out in Scotland and the other devolved nations.
Johnson urged the public to “get boosted now” as he brought the target for giving every adult in England a booster jab has been forward by a month.
The UK Covid alert level was also raised from three to four on Sunday.
It comes as Omicron cases grow rapidly throughout the UK and scientists have been unable to say if it is any less severe than other variants as originally hoped.
The Prime Minister said: “We’ve already seen hospitalisations doubling in a week in South Africa and we have patients with Omicron here in the UK right now.
“At this point our scientists cannot say that Omicron is less severe.
“And even if that proved to be true we already know it is so much more transmissible that a wave of Omicron through a population that was not boosted would risk a level of hospitalisation that could overwhelm our NHS and lead sadly to very many deaths.
“So we must act now. Today we are launching the Omicron emergency booster national mission, unlike anything we’ve done before in the vaccination programme, to get boosted now.
“A fortnight ago I said we would offer every eligible adult a booster by the end of January.
“Today in light of this Omicron emergency I’m bringing that target forward by a whole month.
“Everyone eligible aged 18 and over in England will have the chance to get their booster before the new year.”
Johnson said the UK Government would support the devolved administrations to “accelerate” their own rollouts of third jabs.
He revealed that the decision to speed up the jab rate would mean some NHS appointments would need to be postponed until the new year, arguing there would be “even greater” cancellations if the Omicron wave was allowed to rise.
In a direct plea to GPs, doctors, nurses and others on the NHS front line who he said had “worked incredibly hard” throughout the pandemic, he said: “I must ask you to make another extraordinary effort now, so we can protect you, and your colleagues, and above all protect your patients from even greater pressures next year.”
In Scotland anyone over the age of 30 can book an appointment to get their booster vaccine from Monday with the 18-29 age-group expected to be given the chance later in the week.