The e-ticket I received for my most recent BA booking included a helpful breakdown of taxes and charges. They included a GBP5 surcharge for insurance and security.
IIRC this charge first appeared when the hull insurance rates were hiked after the tragic event almost 10 years ago and security beefed up. After that length of time it must be difficult to argue that it should continue to be a separate item, and not included in the basic ticket price. Unless, of course, insurance rates are likely to fall (they probably have) or security charges reduced (unlikely, given the growth industry it has spawned).