Used to happen to me, with a neighbours visitor turned up, she would always park across my dropped kerbs and open double gates, facing against on-coming trafic so that she could exit and enter car from the pavement she was obstructing.
She had a habit of most annoyingly and very deliberately parking it every week in the same position, and if only she'd park 3ft further on, I would have been able to access my drive ok.
On asking to move, she would very reluctantly moved her car.
Got to a head one winters night as arriving home from work about 9:30 pm in a snow storm, there was the offending car blocking my open gates yet again.
I'd had enough, so I took a wide sweep, and parked at an angle into her car, blocking our road.
I locked it and walked up-to the offenders house, and range the bell.
I politely asked her to move her car, she replied that as I didn't own the pavement, it was public, and also safer for her to exit and enter the car, so she could park there. She was staying overnight due to the weather, and would be going home tomorrow.
I pointed out that I needed to get my car into my garage now, not tomorrow, and asked for her keys so that I could move it.
Very reluctantly she came out of the house and moved her car, shouting and swearing at me in a voice loud enough for an off-duty female police officer who was waiting for me to move hear.
I parked my car up, and went in.
Knock Knock, guess who's at my front door wanting to take a statement!
Statement given, very irate lady then given a police caution for her language.
RESULT, well not quite what I'd hoped for.
Now blamed by her family for phoning the police and getting her into trouble, neighbour not speaking to me, although all others were, but no more parking in front of my gates!
Would I take action again?
YES, I'll give anybody a second chance, and then if they then did it a 3rd time, I'd take action.
Nobody has the right to deny you access or egress from your lawful property.
Remember, always be polite, never ever rude or aggressive; don't retaliate by blocking them in otherwise they will use it against you.
Keep a diary.
Get a basic CCTV covering your driveway.