The guidance for the use of defence assets during civil crises is detailed in the military aid section of the recovery guidance on the Cabinet Office Civil Contingencies Secretariat resilience website at:
which is available to all emergency planners.
In summary, the Civil Contingencies Act 2004 mandates that category 1 responders (emergency services) and category 2 responders (e.g. utility companies) must develop contingency plans for civil crises. Apart from the niche capabilities guaranteed by Defence, the guidance states that armed forces are not to be included in the contingency plans, as it is not possible to define in advance what assets can be provided by Defence. MOD is none the less working with the CCS to define what further Defence capabilities are most likely to be required in the event of a major national crisis.