Two million Britons are going to be invited to have their Covid 19 booster vaccine this week, and a senior health chief is urging everyone to take up the offer.

After the UK recorded its highest number of cases since July 2021 on Sunday 24 October, the NHS medical director Professor Stephen Powis warned “winter is coming” and infections are rising.

The government has all but ruled out a move to Plan B – despite urgent calls to bring in measures to curb the spread of the virus – and instead told the public that Christmas can be saved, if people get their booster jab.

Plan B includes working from home guidance, the mandatory use of face masks and the use of vaccine passports at higher-risk venues and mass gatherings.

But Professor Adam Finn, of the Joint Committee of Vaccination and Immunisation (JCVI), has warned the vaccination programme will not be enough to bring current infection rates under control.

He said people need to be testing themselves, wearing masks and avoiding crowds in enclosed spaces in order to prevent “a real meltdown”.

Professor Peter Openshaw, of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), said Plan B measures “are sensible and not very disruptive”, while vaccine passports have been accepted “very easily in most other western European countries”.

“What we’re facing at the moment is unacceptable, we’ve got roughly one in 55 people infected, which is an astonishingly high rate compared to most other west European countries,” he told BBC Radio 4’s Today programme. “This is connected with the lack of clear messaging about sensible measures that we should all be taking in order to reduce the spread of infection.”

“It’s not problematic to give clear leadership about the use of face masks, and working at home if you can is also not particularly disruptive for many people,” he added.