Refusing to assist a constable is an offence under the common law of England and Wales. The offence is committed if a person refuses, without lawful excuse, to assist a constable who sees a breach of the peace committed or who is assaulted or obstructed when making an arrest, and who, where there is reasonable necessity to do so, calls upon that person to assist him. As a common law offence, it is punishable with an unlimited fine and imprisonment, although it is very rarely prosecuted.