Why are political polls so different?

  • 13/09/2017

The latest Newshub-Reid Research poll has National well in front on 47 percent.

However, that's in contrast with the last Colmar Brunton poll, which has Labour ahead on 43 percent.

For more on this, pollster David Farrar, who John Key personally thanked after his 2014 victory, spoke to Duncan Garner. 

Watch the video for the full interview.