It is not normally a criminal offence, with some exceptions such as defence land with bylaws in place, the railways, for a person merely to trespass on someone else’s land.

Contrary to popular belief, trespass can take place on premises or land that are open to visitors or members of the public. Trespass at these places, which have an implied right of access, only occurs after the landowner or their agent has asked a person to leave and they refuse to do so.

Aggravated trespass is an offence contrary to section 68(1) of the Criminal Justice and Public Order Act 1994, which states the following:

“A person commits the offence of aggravated trespass if he trespasses on land and, in relation to any lawful activity which persons are engaging in or are about to engage in on that or adjoining land, does there anything which is intended by him to have the effect-

(a) of intimidating those persons or any of them so as to deter them or any of them from engaging in that activity;

(b) of obstructing that activity; or

(c) of disrupting that activity.”

Section 68(1) of the Act was amended by virtue of section 59(2) of the Anti-Social Behaviour Act 2003, to remove the requirement that land had to be “in the open air”.

Case law, most notably the case of DPP v Chivers [2010] EWHC 1814 (Admin), has firmly established that land includes inside buildings.

Section 68(4) of the Act permits a constable in uniform to arrest, without warrant, any person he reasonably suspects of committing an offence under section 68(1).

Section 69 of the Act permits the senior police officer present ( this can be a constable) to direct that any person they reasonably suspect of committing aggravated trespass leave the land.