Thanks Not a Boffin.
"BAE has said that they don’t know the exact cost of building such a ship in the UK." there is absolutely nothing they could use as a guideline"
But they are building carriers with nothing to use as a guidline !
Back to my main point. Between SDSR 2010 and SDSR 2015/6 there has been, despite a percieved lack of cash, some big ticket items bought from UK and from foreign nations. I scratch my head wondering why is MMA/MPA such a sacred cow for 2015 when its universally agreed that we need one now.
Easy answer is, that its because it is not going to happen.