Baldric I don't have a link, but the proposal to make it illegal to have a phone even turned on but not being used while the car is being driven has been on the news recently.
Using a hands free phone while driving is already covered in the rules.
It is considered as dangerous as drink driving, as you are partly concentrating on the phone call & not 100% on the road.
The lorry driver who was jailed for causing death by careless driving last week, was convicted because he was using a hands free phone at the time and did not see the parked mini bus until he actually hit it and killed several passengers.