An idea too dangerous for the public to hear of

Via The Englishman I learn that the story of the Treasury's flat tax briefing papers still has legs. I had picked up the original story from the FOIA blog which is a great source for this kind of thing. Out of idle curiosity I downloaded the full FOI disclosure from the Treasury and was surprised that so much had been censored out. Flat tax is, after all, a non-controversial issue - it doesn't represent the stated policy of any of any of the main parties. At the time, I posted a comment on this on the ASI blog to see if anyone could suggest why censorship might be necessary.

This research has now been overtaken by events, the Telegraph having got hold of the uncensored paper, which includes all the arguments in favour of flat tax. It would be nice to think that the Telegraph had used my ASI comment as the cue to dig a bit further, but I suppose this is unlikely.

Anyway, a few questions now need answering:

1. Who took the decision to censor the FOI release and if they haven't been fired, why not?
2. The Treasury's briefing on flat tax was used by the Labour peer, Lord MacKenzie of Luton in a subsequent debate in the House of Lords. In this debate he used all the arguments against flat tax with which the Treasury had briefed him, but did not even acknowledge the positive ones. Does he feel that this was dishonest of him? (Incidentally, it's amazing how the phraseology used by the Treasury turns up almost unaltered in Lord MacKenzie's speech - can't he think for himself?)