My take on the answers given by the government is:
We now accept that there is a capability gap with the lack of a UK MPA, but it's too soon to admit we were wrong to get rid of it, wait until summer 2013 and we'll admit just a little bit more that we need an MPA. We can then blame changing circumstances on the fact that we need an off the shelf replacement and not that we trod on our d***s when we cancelled the MRA4.