``It is with a very heavy heart that I must tell you we cannot proceed with Christmas as planned,'' Johnson said.

Calls were made to sack Johnson's senior adviser Dominic Cummings after he traveled 400 km to northern England while his wife showed COVID-19 symptoms.

Heathrow Airport has proposed Britain should set up “travel bubbles” with low-risk countries exempt from the requirement.

The current number being conducted is about 10,000 a day.

“We estimate that in the absence of interventions, COVID-19 would have resulted in 7.0 billion infections and 40 million deaths globally this year,” the report reads.

With some doctors saying they felt like "cannon fodder," the government said the military would help ship millions of items of personal protective equipment (PPE) including masks to healthcare workers who have complained of shortages.

Britain has so far held off from introducing measures to restrict movement or cancel large gatherings for fear of hurting the economy.