But Mr Assadi he accepted that that was not the only indication of voting intention.

BBC: Sectarian tensions stalk Iraq elections

But, as with voting intention, the various polls on independence point to the nature of the campaign itself, to the two visions of independence.

BBC: Act of Union

By cross-referencing data on things like age, health, occupation, personal finances and property with voting intention, the parties are able to make informed guesses about where their support is and where they might pick up more votes.

ECONOMIST: The election