No idea, all I know is that they've finally realised that the 'NATS sets the market rate' argument about salaries is way off the mark and they've moved onto 'what will our customers think if we hand out big pay rises?'
This year's pay rise will be funded out of money earned this year.
Oh I'm sure they have an excuse all lined up not to part with the readies (see above for a few).
It's all crap.