From Wikipedia.....
In England and Wales, the term squatting usually refers to occupying an empty house in a city. The owner of the house must go through various legal proceedings before evicting squatters. Squatting is regarded in law as a civil, not a criminal, matter. However, if there is evidence of forced entry, then this is regarded as criminal damage, and the police have the powers to remove the occupants. If the squatter legally occupies the house, then the owner must prove in court that they have a right to live in the property and that the squatter does not, while the squatter has the opportunity to claim there is not sufficient proof or that the proper legal steps have not been taken. In order to occupy a house legally, a squatter must have exclusive access to that property, that is, be able to open and lock an entrance. The property should be secure in the same way as a normal residence, with no broken windows or locks.
The bit I put in bold annoyed me, If I came home to find Squatters in my house, I then have to prove to a court that it is my home and not theirs!! On a side note, cant I just wait for all the squatters to go out shopping (for example) then get into my house and lock them out. Or do squatters normally leave at least one person inside the house at all times?