“And if you haven’t yet had your first and second vaccines, it is not too late,” Javid said. “The NHS will always be there to welcome you with open arms.”

"If we all come together and play our part, we can get through this challenging winter, avoid a return to restrictions, and enjoy Christmas."

Javid warned that immunity against Covid-19 begins to wane after six months, especially for older and vulnerable people.

The health secretary said 9 million boosters have been administered across the UK. From Monday, people in England can book an appointment for a booster jab a month in advance. The government hopes the new service will help speed up the vaccination campaign.

Christina Pagel, a member of the Independent Scientific Advisory Group for Emergencies (Independent SAGE), said on Saturday, “If we want the booster programme to save Christmas we’re going to have to do it a hell of a lot quicker.”