You can report them to the council and they will make a note of the complaint in case they have further complaints ....In which case they can then act and issue fines. if you have evidence as I did recently when I submitted dashcam footage of a UBER taxi driver littering in Wakefield they will act immediately and issue the fine. (Turns out the Taxi driver I captured in the video footage was from Burnley having his lunch in a lay-by and decided it was acceptable to throw his Lancashire rubbish in Gods own County! (Turns out he was wrong )
So what you do is, ask them very politely "Do you love your country" If they say yes, you reply "Well why do you treat it like **** then?" All in the sweetest way possible. If they say "No" then you reply, "Yes, it really shows".