But Downing Street are being clear that they have no official timetable for his return, says BBC political correspondent Leila Nathoo.

We’re starting to see signs he is back in action but there is no firm commitment for when he will be back in public, our correspondent adds.

Spokespeople say he is not doing government work although he has spoken to Dominic Raab, the first secretary of state who is deputising for him.

He has also spoken to the Queen over the phone and Donald Trump.

The US president has said Johnson sounded "incredible" during their phone conversation a few days ago - the "old Boris, tremendous energy, tremendous drive".