From next month the First Group, which claims to run one in five bus services across the UK, will prohibit its entire 135,000 workforce from using mobiles on the move.

The policy is in response to findings from the Transport Research Laboratory showing how driving performance is “significantly impaired” when holding a telephone conversation.

The research found that driver performance while making a hands-free mobile conversation is at a lower level than when drink-driving. “When we reviewed the evidence we decided to implement this new policy,” said chief executive Moir Lockhead. The move follows high profile press reports this week suggesting the Crown Prosecution Service will use new rules to seek jail sentences for drivers involved in accidents whilst using mobiles phones. While drivers caught using their hand-held mobiles will continue to face the standard penalty of a fine and points, the new rules, announced in September, can be used by prosecutors to press for dangerous driving charges which carry a maximum two year sentence.