Back in 2012 I sent a few queries to the Electoral Commission, just to confirm a few things for my records. Here is their reply, received on 23 May 2012:
Thank you for contacting the Electoral Commission following the Political Polling Forum organised by AMRO, held at Parliament on 9 May 2012.
One of the panel members representing a polling company at the event commented that where a voter was surveyed prior to an election and they indicated they had already voted their voting preferences were still recorded in the poll.
Your query to the Commission is whether it is legal to include people who have already voted in advance in pre-election polling.
Section 197(1)(d) of the Electoral Act 1993 makes it an offence for a person at any time before the close of the poll, to conduct in relation to the election a public opinion poll of persons voting before polling day.
This provision makes it clear that it is not permissible to conduct an exit poll of voters prior to election day. A person who commits an offence under section 197 is liable to a fine of up to $20,000.
Advance votes are cast in the 17 days before election day. There has been an increase in advance voting over recent elections, with 334,558 (or 14.7%) of voters voting before election day at the 2011 General Election. Consequently, care needs to be taken if random polling of electors is conducted during the advance voting period to ensure section 197(1)(d) is not contravened.
In the Commission’s view the questions put to individuals polled and the reporting of any results need to be worded in a way that ensures that they do not ask or disclose how people have actually voted. For example, people could be asked ‘which party they would vote for if they had to vote now?’. In the alternative, a polling company may chose not to poll any person who has already voted.
I hope this answers you query. Please feel free to circulate this response to other members of the panel who were present at the recent political polling forum event.
So essentially, exit polls are not allowed.
You can poll advance voters, as long as you don’t ask how they voted. To my knowledge, most polling companies ask ‘who would you vote for if an election was held today/tomorrow’, or something very similar. They do this because the purpose of a poll is to measure voter sentiment at the time of the poll, not to predict it on Election Day.
That may seem like a small distinction – but it’s really quite a big one when you think about it.