Strangely, it's not a criminal offense to park on somebody elses driveway in the UK. It is classified as trespassing and therefore is a civil matter, not a criminal one. What this means is that the police are very unlikely to get involved unless the driver of the vehicle is committing some other offense.

In the UK, the law regarding parking in front of a driveway is a bit of a "grey area" but generally favors the homeowner if there is a dropped kerb. According to the Highway Code (Rule 243), drivers should not park in front of an entrance to a property. If a vehicle is parked across a dropped kerb, it is considered an "obstruction," and the local council or the police have the power to issue a Penalty Charge Notice (PCN) or even tow the vehicle away. However, if there is no dropped kerb, it is technically not illegal to park there, though it is considered very poor etiquette. Interestingly, if a car is parked on your actual private driveway without permission, it is technically a civil trespass matter rather than a criminal one, which makes it much harder for the police to intervene. If someone is blocking you into your driveway (preventing you from leaving), the police are more likely to act as this is seen as an illegal obstruction of the highway. If they are blocking you out of your driveway, it is unfortunately seen as a lower priority.