It is named 'evil cabal' after a remark by former leader Mike Storey (Lib Dem) about Sir David and his supporters.
The two fell out last year after a series of emails in which the leader had made indiscreet remarks about the chief executive were published (LGC, 2 June 2005).
Mr Storey resigned last November and Sir David retired from the council in March.
A message to readers said: 'There is a huge increase in the number of hits after 6pm - perhaps all council staff are rushing home to log in to their non-council computers and find out more about the cabalists.'
The polemic blog features alleged intrigues against Mr Storey, as well as Sir David's severance arrangements, and relations between senior officers.
A council spokesman refused to comment on whether the blog had been blocked.
He said: 'There are about two million sites blocked by the council because people should use their computers only for work-related stuff.'
Kiron Reid, a senior member of the ruling Lib Dem group, said: 'The council's decision to stick to a 'no comment' line on this only fuels the rumour mill.'