I agree with cirrusfrance!
There's no doubt that the MR2, P3, Globalhawk etc are extremely capable platforms, but they're also extremely expensive and probably as importantly, are not available right now.
I think the Diamond to which Cirrus refers, is available for significantly less than a £million a pop, would have a crew 85% smaller than the MR2 and would be available now!
Don't forget that Defence is completely broke. It's surprising to me that the several £billion contract for the MRA4 has not been questioned more fully. I don't doubt that it will be a capable beast, but there are alternatives for a fraction of the cost.
ISR from light, prop driven aircraft is without doubt the way ahead. UK PLC has already recognised this. Let's forget the politics and get what we need, for a price we can afford.