I brought this up a few months back in the "Wakey wakey manning" thread.
Before discussing the light blue it's interesting to note the army have reached their 82k manning level and are hurtling south past it! Probably the only element of FF2020 that will happen.....
The light blue seem happy to be still shrinking at over 100 a month. Unless recruitment nearly doubles they too will reach the FF2020 figure of 31500 by next April. All of this is from the MOD manning figures before someone shouts security.
It's a complex beast of established posts no longer needed and unestablshed posts that are manned but on the black economy, mixed with the 1000 or so folks that have left and on ressetlement but still on the books and throughput from training. Mannings job is not easy but they are working to a smaller Air Force plan than SDSR 10 direction. Equally, being at or below your 2020 figure in 2015 in time for the defence review is not really stating your case for more people.