“In a statement on Friday, Transport Ministry spokesman John Summers said the Road User Amendment Rule restricting the use of cellphones in cars, due to take effect in November, meant drivers would not be able to look at a navigation aid on a mobile phone when driving, even if it was mounted in a hands-free kit on their dashboard.

But yesterday afternoon, Mr Joyce said: “It is not the intent of the rule to make it illegal for motorists to use the satellite navigation or music functions of their cellphones, provided these are mounted in the vehicle and are manipulated infrequently.”

The rule would be amended to make that clear.”