Well, ideally none of them if we wish to continue punching above our weight. But times are hard and the axe is being sharpened (again) - but not for all. From the Telegraph we learn that some regiments are apparently 'untouchables':
... understood to include the entire Household Division - the Grenadier, Coldstream, Scots, Irish and Welsh Guards as well as the Household Cavalry, composed of the Blues and Royals and the Life Guards.
The Life Guards ?! I cannot think of a more useless outfit. (I suffered under the size 10 Boot DMS of a brutal Corporal Major of horse at the RMA, but that has nothing to do with it, of course.) My old mate General Sir Peter Wall, CGS, is a down-to-earth Sapper and I can't see him harbouring any great sentiment in favour of these wastrels whose ceremonial tasks should be outsourced to Equity.
Mark my words, Cameron's riding set has been lobbying again: they've persuaded him that HM the Q would be displeased (not to mention unhappiness among the Wuperts). Not good.