Why does ur neighbour parks in front of ur gate ? is it the only space available or is it convenient for him ? put yourself in his shoes and see what options do you have.
ur car is inside when he blocks the gate .. meaning, he parks later why don't u park your car outside ur gate for a few days, so he could find and get used to, another location
if all else fails ... create emergency late at night or whenever he is sleeping and call him to move his car .. do it a few times very frequently and he'll get the message
is he a tenant or the owner of the house .. call its owner .. tell him you will launch a complaint with the local development authority for illegal use of public property (check for the process and rules) ..
