The Light Aircraft Association's response
This has been posted on gliderpilot.net (which had been out of action for some weeks due to a hacker). It's a very thorough and well reasoned response and well worth reading in full.
www.lightaircraftassociation.co.uk/Consultation/ModeS%20Sub%20Docs/LAA%20Draft%20Mode%20S%20Consultation%20Response.pdf