Data released by the UK Health Security Agency (HSA) reveal that six London boroughs are among the ten council areas which have seen the highest number of confirmed and suspected cases so far.
The HSA also confirmed that lateral flow tests appear to be as effective in identifying Omicron infections as they are in picking up the Delta strain.
Dr Jenny Harries, the agency’s chief executive, said: “Our data shows that lateral flow device tests are similarly able to detect Covid-19 in individuals who have been exposed to Omicron as in those exposed to previous variants.
“This is very encouraging. As we all work to limit the high levels of transmission of this variant over the Christmas period, we are urging people to test regularly, particularly before attending social gatherings.
“As always, the booster vaccine remains the best protection against infection. Please come forward to receive your booster as soon as possible.”
Testing for Omicron cases varies by area, and is particularly low in the South West.
Here are the 10 parts of the country which recorded the highest combined number of confirmed and suspected Omicron cases, up to December 15.