Thanks for the info Brotherton. These concerned adults do appear to be the usual suspects to me, and are up to their tricks as usual!Here they are:
News [Coalition to stop the use of Child Soldiers]
and here is the Australian military policy which 'complies with both the spirit and the letter of the Optional Protocol'.
The campaigners are arguing that the MOD has retained a couple of options to contravene the Protocol if operational circumstances demand. That is the nub of the argument. Even if, in practice, U18s are not deployed on operations (except by admin cock-up) and even if they can leave under the age of 18 with a parental letter (either DAOR or as an 'unhappy soldier'). It's not so much fluffy liberal PC bollox as complying with UN agreements that the UK Govt has signed up to with 'a bit of wriggle room'.
PS. Even Australia has some wriggle as well if circumstances demand on page 8, eg on a ship suddenly deployed into hostilities. cf HMS Cumberland could perhaps have had a 17 year old aboard when diverted to Benghazi..
I'll be honest, that pissed me off greatly. I mean "child soldiers" FFS, what the actual hell?