After much thought, I now suggest that:
1. With effect from 1 Apr 08, increased surveillance and collison protection should be introduced. This must be reasonable, affordable and proportionate to the degree of protection sought.
2. With effect from 1 Apr 08, Mode A should no longer be permitted within UK airspace.
3. No new Mode C installations should be approved after 31 Mar 10.
4. Minimum transponder requirements after 31 Mar 08 should be as per the following table:
Sorry if it's a little large. Anyone who wishes to cut and paste this into a response to the CAA RIA, please feel free to do so.