"You cannot use a firearm, even an air rifle afaik, within 50metres of a road, public footpath or bridal path.
They can have their gun confiscated with no compensation if they do and their gun licences revoked. My DH clay shoots so I know a little bit about gun law."
The law you're looking for is Highways Act 1980, Section 161(2b):
61 Penalties for causing certain kinds of danger or annoyance.
...
(2)If a person without lawful authority or excuse?
(a)lights any fire on or over a highway which consists of or comprises a carriageway; or
(b)discharges any firearm or firework within 50 feet of the centre of such a highway,
and in consequence a user of the highway is injured, interrupted or endangered, that person is guilty of an offence and liable to a fine not exceeding level 3 on the standard scale."
So yes you can shoot near a road. And highway in this case means any right of way for vehicular traffic, so not footpaths.
Although you can shoot near and over such highways, the law stipulates that you must not cause alarm or distress (or injury!) to any users of that highway. As you can see, the law makes provision for a fine. It is unlikely one would lose their certificate or guns over such a conviction unless it were shown that the complainant was endangered, which would show the holder to be unfit.
By way of example, we have a road along one side of one of our fields. If I need to have a bash at a troublesome fox around lambing time or we're suffering a surplus of rabbits, then for obvious reasons, the safest way to shoot is with your back to the road hedge and shoot into the field - away from the road and towards a hill (which makes a good backstop, not that I miss :p ). If someone came along in an open topped car and was disturbed by the noise, they might get a conviction against me under the highways act (although I doubt the CPS would consider it in the public interests to pursue a prosecution). However, I probably wouldn't lose my ticket since I was shooting in a safe and responsible manner - which is all the firearms unit care about. That being rather more important than whether someone's delicacies are offended by what I (legally) do on my own land to protect the livestock.
I should point out it's a quiet lane where the only pedestrians are our neighbours coming to us or vice versa. If it were near a town or somewhere you regularly had pedestrians, some other orientation would have to suffice, or we'd try and go down from a cartridge rifle to an air rifle that was quieter and more discreet, although for fox it needs to be cartridge or shotgun for a clean and humane kill.
Also, shots must not leave the boundary of the land (covered separately in the Firearms Act), but that's kinda obvious.