The drivers may be committing an offence under Section 86 of the Traffic Management Act 2004 which says,
"Prohibition of parking at dropped footways
etc.
(1)In a special enforcement area a vehicle must not be parked on the carriageway adjacent to a footway, cycle track or verge where—
(a)the footway, cycle track or verge has been lowered to meet the level of the carriageway for the purpose of—
(i)assisting pedestrians crossing the carriageway,
(ii)assisting cyclists entering or leaving the carriageway, or
(iii)assisting vehicles entering or leaving the carriageway across the footway, cycle track or verge; or
(b)the carriageway has, for a purpose within paragraph (a)(i) to (iii), been raised to meet the level of the footway, cycle track or verge.
This is subject to the following exceptions.
....
....
(3)The second exception is where the vehicle is parked outside residential premises by or with the consent (but not consent given for reward) of the occupier of the premises.
This exception does not apply in the case of a shared driveway. "
I suggest you 'phone your council to see if you're in a special enforcement area and if no, ask them if they intend to take action under Schedule 10 of the same Act to make it a special enforcement area.