And Roffa, i think you are clearly missing the point here. We signed up to the £10k, yes, we are not complaining about that. How would you like someone with less experience than you to be earning more than you? Think about that for a while.
Okay, I've thought about it and... no, doesn't raise any hackles.
If you were to be employed by NATS in the non operational side of the business, thanks to elements of performance related pay it's quite possible someone with a bit less experience than you could be getting a higher rate for the same job title.
It's an unfortunate anomaly but not at all a unique one, just try to keep an eye on the bigger picture. You have hopefully got a long career ahead of you in NATS, well if you end up in NERL anyway, and you'll find out soon enough that there are plenty of other inconsistencies and issues around. Look on this as a learning experience inducting you into the joys of working for this particular company.