Dominic Cummings’ future in question, after row with Boris Johnson

How long will Dominic Cummings remain as Boris Johnson’s most senior adviser?

The answer to that remains uncertain after the resignation of Downing Street’s head of communications Lee Cain last night. Mr Cummings is said to be unhappy at the departure of his close ally.

But some Conservative MPs say they are unhappy about the way Downing Street is being run, and they would rather like Mr Cummings to follow his friend out of the door.