THS
Err, that commodity is necessary for ALL ops (land, sea, air) and if you look at what they've bought it's all non-developmental. The alternative led to a lot of cost escalation with CdeG.
Jacko
Whether the NAO figure is a UPC or not, I can't see an argument that doesn't have a £1Bn-plus impact on the EP every year for Tiffy, which I believe was your point.
As for costing more than £5Bn, as one who has spent nearly 20 years in the shipbuilding industry, I can tell you that MoD was being seen off good and proper at £4Bn. The delay will certainly ensure that they do cost £4Bn though. However, there aren't enough systems in the ship to escalate by another billion - not to say BVT won't try obviously.