Vehicles used for business purposes and shared by more than one person were included in the first draft of the new Health Bill, due to become law next summer.
But a Commons vote last week failed to clarify the position by delaying a decision on the possible extension to the ban.
Smoking will be permitted in private cars but banned for the driver and passengers of taxis. It could include company cars but these might escape if everyone at the company smokes. The Department of Health will launch a three-month consultation period on some of the Bill’s trickier issues once the legislation passes the Lords this summer.
Executives at fleet management company Masterlease say fleets should favour a total ban now rather than wait for it to become law in the future.
Adrian Baldwin, Masterlease marketing and communications manager, said: ‘If passive smoking is an issue in pubs and bars, then it is going to become an issue in an even more confined space of a vehicle shared with work colleagues, whether they be business associates who share lifts to meetings or plumbers and refuse collectors.
'It is not just about getting caught and who pays the fine but, more importantly, about the health and safety of staff who breathe in other’s fumes on long business journeys or on their way to and from work.
‘Who is to say that those exposed to passive smoking in such circumstances could not issue their own civil actions against companies which fail to put in the relevant guidelines?’
From next month, a smoking ban in Scotland will affect van drivers. Company cars are exempt.