TrimStab
The AirTanker PFI is apparently going to cost in the region of £400Mil per year to implement and that is with a fairly well defined set of requirements. MRA4 was binned because it was going to cost £200mil per year (and we had already paid for the hardware). How much is a complex Multi-mission aircraft going to cost under a PFI contract? More than we can afford it would seem.
If you don't need (read can't afford) complexity and flexibilty then a cheap buy of some CASA 235/239s or ATR72s will at least allow you to maintain some degree of capability whilst retaining skills and knowledge. Unfortunately, the hard won skills and knowledge focussed at Kinloss over the last 75 years or so is leaking faster than Japanese reactor.