In article , Nick Maclaren
writes

Some 40 years ago, there was a case where a farmer tried to get
an injunction to prevent gypsies from picking mushrooms from his
fields. The case hinged on whether the mushrooms were his
property (i.e. Norman rather than Roman law), and hence whether
the gypsies' action constituted trespass. But, without evidence
of damage, you cannot get an injunction to prevent someone passing
over your property, as there is no tort.

We've had a Tory government since then who changed the law of trespass.
If you have an unfenced area you can put up a Highways Act notice
stating that the land is not dedicated as a highway, as you will see on
many buildings on big cities. This is to prevent an area becoming a
highway through use. You can enforce this notice if required.

Jon
--
Jon Rouse