Presuming any govt who end up in charge next year will resent spending cash on defence, a good way to run down the sector might just be to chop pensions. If you ask Joe Civvy what 'our boys' need, they'll undoubtedly say 'helicopters, body armour and boots' - pensions aren't patriotic bits of kit needed at all costs in foreign lands, and there is unlikely to be much of an outcry from the general public if the apparently generous military pension is brought down to that of the general populous.
That will probably cause an exodus, certainly in older arms like the RAF, but as has been seen during the transition to expeditionary warfare, those who left - and there have been a fair old number - have been replaced by those who know nothing but expeditionary warfare; so it will be with pensions - although I can see it being done in the same way as AFPS05 was introduced, with newcomers only being given the chance to join the new scheme, as those in the old are gradually replaced.
If this happens there may be some fringe benefits though - those who are serving little more than themselves may opt to leave earlier, and the sycophants, whilst often genetically driven to do so, may see evolution leave them behind.