Event attendees who have not had a third Covid-19 vaccination could be prevented from entering large venues, according to a Government source.

The Times has reported that health secretary Sajid Javid is a leading supporter of making booster jabs a mandatory requirement for vaccine passports, and that Government sources have suggested the move is “inevitable”.

The idea was discussed by the Government’s Covid-O committee earlier this week.

A Government source told the newspaper: “The prime minister is very open to it. Both Chris [chief medical officer for England Chris Whitty] and Patrick [chief scientific adviser Patrick Vallance] were supportive. This is about incentivising people to get their jabs.”

It is expected that the plans would not be implemented until February. Prime minister Boris Johnson has confirmed Plan B restrictions will remain in place until the end of January.