The MoD has to make a definite decision. They can't just keep dithering about then cancel or delay (don't worry 18 more mths .... 18 more mths) the MR4 at the last minute - wasted monies and the MR2 might not make it.
If it's P-8 (~2013/4), an interim aircraft might the way to go or, just reduce operations. However, the P-3 Orions aren't looking too flash either.