For what’s it’s worth:
The What UK Thinks: EU Poll of Polls is based on the average share of the vote for ‘Leave’ and ‘Remain’ in the six most recent polls of voting intentions in the EU Referendum.
The bar chart to the right shows the average of the six most recent polls, the fieldwork for which was conducted between 14 and 20 June 2016. It is based on two (online) polls by YouGov, two (phone) polls by Survation, one (online) poll by Opinium, and one (phone) poll by ORB. The most recent additions are one poll by YouGov (17-19 June), one by ORB (14-19 June) and one by Survation (20 June).
The line graph below shows how the Poll of Polls has changed since polling based on the question that will appear on the ballot paper began in September 2015. The date at the bottom of the graph represents the date on which interviewing for the most recent poll in that set of six was concluded. Details of which companies’ polls are included in each estimate can be seen as you drag your cursor along the line graph.
Note the series includes both polls that were only conducted in Great Britain and those that were conducted across the United Kingdom as a whole.