Brandon Lewis has been forced to explain himself after being pictured travelling in his ministerial car without a face mask.
Downing Street has told ministers that they must cover up when travelling in government vehicles, despite a loophole in the rules for chauffer-driven cars.
A source close to the minister said he had removed his mask to drink a cup of coffee in the car.
Passengers in taxis and private hire cars are required to wear masks – with fines of £200 for flouting the rules.
The fines, which reduce to £100 if paid within 14 days, can stretch to £6,400 for repeated breaches.
This comes just over a week after Matt Hancock was snapped not wearing a mask while travelling to the Department of Health and Social Care in a ministerial car, despite repeatedly asking members of the public to cover up.
The health minister was then filmed recording a message in Royal Berkshire Hospital in Reading on Tuesday without a mask, which is in breach of government guidelines.
A source close to the Health Secretary said he was “filmed in a socially distanced way” during the hospital clip and that he “wore a mask for the rest of the visit”.