As I understand it, following the last lot of firemen's strikes, the laws regarding the use of Service personnel for MACA tasks was changed so that local authorites now have to pay MOD for the support provided. This was to ensure that local authorities had plans in place for disaster relief that were a little more in-depth than 'get some soldiers to do it' which had previously been the case in some areas. MACA is now a wpn of last resort due to the cost.