United Kingdom Prime Minister Boris Johnson has said England will continue with its current Plan B COVID-19 control measures for now, rather than take any further steps.

During a media briefing on Tuesday, he said the weeks ahead would be challenging, but despite the significant increase in case numbers, there is a “substantial” level of immunity in the population.

Johnson said there is a chance to “ride out this Omicron wave without shutting down our country once again”.

Plan B measures include wearing masks on public transport and in some indoor venues, and working from home where possible.

On Tuesday, more than 200,000 people were reported as testing positive for COVID-19 across the whole of the UK.

Johnson said anyone who thinks the battle against the virus is over is profoundly wrong.

“This is a moment for utmost caution,” he said, adding that the Omicron variant is milder and cases are not translating into the same intensive care demand as previous waves.

As the National Health Service moves to what he called a “war footing”, Johnson said he will recommend to his cabinet on Wednesday that Plan B remains in place.

“We can keep our schools and our businesses open, and we can find a way to live with this virus,” he said.

“But the weeks ahead are going to be challenging, both here in the UK and across the world.”

It was announced that 100,000 critical workers, such as those in food processing sector, transport and border force, will from Jan 10 receive daily lateral flow tests, in order to counter COVID-19 related staff shortages.

The government will send test kits directly to these workers.

Johnson also urged people to get vaccinated and thanked those “who assisted in this extraordinary national effort over Christmas” in the vaccination drive.

But he said around 9 million people have not yet had a booster, and that some 90 percent of people in intensive care with COVID-19 have not had their booster shot, and up to 60 percent had not had any vaccination at all.

He also pointed out that some countries already require boosters for people to be considered fully vaccinated.

Asked if further restrictions will be imposed in England, Johnson said the situation will be monitored very closely and he “can’t rule anything out”.