§ Mr. Burden
To ask the Secretary of State for Defence if he will list the criteria for military campaigns to be classified as active service. 
§ Dr. Reid
The definition of "on active service" is laid down by statute in the Service Discipline Acts. A force on active service is one engaged in operations against the enemy, or engaged elsewhere than in the United Kingdom in operations for the protection of life or property, or (subject to the provisions of the relevant section in the three Acts) is in military occupation of a foreign country. In relation to a person, it means that he or she is serving in or with a force which is on active service.