It marks the second consecutive day that more than 100 cases of the new variant have been reported.
115 of the cases were in England, taking its total up to 448, according to latest figures from the UK Health Security Agency.
A further nine were reported in Scotland, taking its total up to 108 confirmed Omicron cases.
Meanwhile, Wales identified a further four cases, meaning it has recorded nine overall.
Northern Ireland has also reported its first three cases of the Omicron variant.
He explained that this means people are becoming infected within the community and not all cases are linked to travel.
Boris Johnson is reportedly considering whether to introduce Plan B measures including work from home orders and Covid passports in a bid to limit the spread of Omicron which is said to double every two days.
It comes as leading epidemiologist Professor Neil Ferguson said a January lockdown could not be ruled out if hospitalisations spiral over Christmas and into the New Year.
Number 10, which discussed fresh measures to prevent the spread of the virus yesterday, did not deny the rumours that it was planning to put in place its “Plan B”.
Downing Street sources said “no decisions have been made” yet.
Booster jab bookings opened for seven million people aged 40 and over Wednesday and the wait for a third dose has been cut from six months to three amid growing concern about the new strain.
