Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what the (a) average and (b) maximum period for duty in battle zones is for (i) army, (ii) Royal Navy and (iii) RAF personnel.

Each Service has Harmony Guidelines for the amount of time any individual should spend away from their home unit (whether in battle zones or performing other duties) including time on deployment.

A breach of Individual Harmony Guidelines occurs when Service personnel experience separated service for longer than the period outlined in Individual Harmony Guidelines. These are: for the Royal Navy/Royal Marines, no more than 660 days away over a 36 month period; for the Army, no more than 498 days away away over a 36 month period; and for the Royal Air Force, no more than 468 days away over a 36 month period. These guidelines are different for each Service reflecting the differing structures of, and differing roles and duties undertaken by, each Service.

The latest figures on single Service levels of harmony breaches were released by the Department as an official statistic (as part of the Monthly Service Personnel Statistics publication) on 10 September 2015 and are linked below.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/459461/Service_Personnel_Statistics-1-August-2015.pdf#page=10