The government is to announce new powers making it easier to mobilise tens of thousands of former armed forces personnel to prepare for war.
New rules will mean reservists remain on call for an extra decade, and lower the threshold for them being called into service.
The changes will form part of legislation for the armed forces being published in parliament later.
While some of its provisions are technical measures the government has to renew at regular intervals, other parts of the legislation are seen by ministers as a crucial part of the conversation about Britain’s readiness for conflict.
The measures affect the segments of the armed forces reserve who are former service personnel rather than volunteers – known as the strategic reserve.
Currently, the age limit for the strategic reserve is 55. This will change to 65.
The threshold for members of the strategic reserve to be mobilised will change too.
Under existing rules they are called upon in the scenario of “national danger, great emergency or attack in the UK”.
That threshold will be lowered to “warlike preparations”, which is already the threshold for reservists who have left active service in the past few years.
The changes will come into force next year, if passed by parliament.
The government estimates that there are around 95,000 members of the strategic reserve.
Last year the Strategic Defence Review called on the government to “reinvigorate the relationship with the strategic reserves”.
