Currently, trespass (being on land without permission) is a civil offence.
However, the police have no power to act. A landowner or his agent may ask the trespasser to leave and subsequently may use “reasonable force” to remove them.
“Reasonable force” can be interpreted in many ways by the courts, and the use of force could leave you open to prosecution. We do not recommend using any force to remove trespassers.
A court injunction can be obtained against possible repeat offenders. Someone who contravenes an injunction can be held in contempt of court.
In Scotland, legislation relating to trespass is more complicated and it is sometimes argued that the offence does not exist. However, anyone causing actual damage or disruption may be requested to leave. There is also recourse to an interdict, similar to an injunction, to guard against repeat offences.