Thank you. First of all, this conduct could potentially amount to harassment, which can be either a civil or a criminal offence. The Protection from Harassment Act 1997 states that a person must not pursue a course of conduct, which amounts to harassment of another and which he or she knows or ought to know amounts to harassment. Although there is no definition of what harassment is, it would usually include alarming a person or causing them distress and must have occurred on at least two occasions.
How this matter is dealt with would depend on whether the victim wants to take it down the civil route or the criminal one, or even both.
If a civil claim is made in the courts, it must be initiated within 6 years of the alleged act(s) of harassment taking place. The court can make an order instructing the harasser to stop their behaviour. If they still do not stop harassing the victim it would become a criminal offence and they can be prosecuted in the criminal courts. It is also possible to seek financial compensation if financial or emotional losses have been suffered (e.g. causing severe anxiety or distress).
If the matter is reported to the police instead and they take it further and prosecute, the punishment for harassment can be imprisonment and/or a fine. A court may also impose a restraining order for the purpose of protecting the victim.
Before the courts or the police get involved it may be better to try and resolve this directly with the harasser. They should be warned that their actions are being treated as harassment under the Protection from Harassment Act 1997 and that unless they stop what they are doing they will be reported to the police and legal action under harassment legislation taken against them. If that does not help, the matter can be taken further either by contacting the police and letting them deal with it as they see fit, or starting civil court action by making a claim for harassment.
You can also consider an internal grievance through the employer but it depends on whether you want them to know or not, so that is up to you.
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