I prepared this chart as my response to the media chortling and blogosphere despair over the Labour Party's polling. It's of course dedicated to Scott of Imperator Fish.
I downloaded the 2009-2011 polls data lovingly recorded on Wikipedia for Labour and the Greens. Lots of dots. To keep it simple, I put in a linear regression trend line through each series of dots.
On that basis, there is no real trend in either the Labour or the Greens polling! And it's just not valid to say "Labour's polling is on a downward trend".
So for Labour the bad news is not extremely bad, but it still fairly bad, as there is still a consistent trend of a 20 point gap between Labour and National.