really - I see the council cutting hedges all the time, and often the actual plants are growing from adjacent fields. I'd assume the council has the right to cut whatever they want if it's obstructing a public road.
The problem here may be that the "road" sounds like it's only used by one or two houses - pretty much bottom of the priority list for any council. I think this is a particular problem in Ireland where we have lot more road per head than in other jurisdictions, where minor lanes like this are generally privately owned and maintained.