joko is right of course, but it's not always that simple. Nobody can comment properly without knowing the circumstances, but it is possible for a court to issue an injunction which might, for example, prevent the person being within a certain distance of your home. It is not easy to make the application yourself, so you really need to see a solicitor.
If someone enters your home without your consent they are a trespasser and you can use reasonable force to remove them. In reality you would ask the police to do this for you to avoid any problems and if they refused to leave they could be arrested for a breach of the peace.