The Council Chamber in Rayleigh , where my District Council meets, seldoms sees any real nastiness. A few months ago I made a somewhat barbed (but not nasty) speech concerning a broken pledge by the Conservative Group and some time afterwards one of the best of the Tories made the comment that he had now seen some vitriol in the Council Chamber. My response was that you have to be able to distinguish between vitriol and antiseptic....
However if you are looking for vitriol have a look at this blog from Jane Griffiths , ex Labour MP for Reading East. Her "About Me" section is a good starting point: "I was Labour MP for Reading East from 1997-2005. Some boys in the Reading Labour party decided they had had enough of the uppity girl who wouldn't do as they said so they sacked me. The seat is of course now Conservative, which is what they, especially the Reading West MP Martin Salter, wanted"
Vitriol or Antiseptic?
The credit goes to Iain Dale for providing a link. (He's not had a good political year himself, but seems to have avoided any bitterness !)