Work or on duty ... If we're going to be penickity there is a difference. And unless the formal position has changed, military personnel are assessed as being on duty 24/7 as the MOD and Treasury agreed back in 1977 when they were trying to decide on the tax status of travel warrants, HTD etc.
On the 5 July 1977, the Chief Secretary to the Treasury, Joel Barnett, wrote to the then Secretary of State for Defence, Fred Mulley, in which he set out an agreed position on the home to duty travel allowance for members of the armed forces. The relevant parts of this letter are:
(At a meeting on 29 June 1977) I agreed that the Government should introduce legislation at the Report Stage of the Finance Bill to exempt both (travel warrants and home to duty travel allowance) from tax in the hands of members of the Services.
..but the Revenue tell me that it would be possible for them to justify treating the allowance as not liable to tax under existing law
A serviceman is always on duty
his travel between home and barracks is between two places of duty rather than from home to duty, and the expenses of that travel are not taxable.
So are we paid for being on duty or for time spent sitting in the cockpit, on the Ops desk, in SHQ? If the former and we are still deemed as being on duty 24/7, and are therefore paid as such, then there probably are quite a few people not getting the living wage. Probably not that simple though, with no doubt numerous clauses, caveats and MOD policy decisions based on what fits at any given time.