8. Declaration of war.

In order to constitute a legal state of war between the United Kingdom and a foreign state there must be either a formal declaration of war by the Crown1 or hostilities must have been commenced by the authority of the Crown on the basis that those hostilities will constitute a 'war'2. Thus hostilities against a foreign state, even though the whole nation joins in, without the concurrence of the executive do not constitute a legal state of war or a legal breach of the peaceful relations existing between the two countries