1. For the British Polling Council / Market Research Society 19 June 2015 Voting Intention polling

2. Anticipated challenges in advance of final poll

3. Things we were on the look out for 3 Similar to 2010 – younger voters who said they would vote Lib Dem did not turn out to vote Differential turnout by age A proportion of those who said they would vote Labour/some other party would actually vote Conservative Shy Tories ‘Reluctant Tories’ driven by fear of Lab/SNP Government and/or economic factors Late swing

4. Late Swing: The “Yes, Yes, Noes” 1.Best PM question asked from 4 th -26 th March & 31 st March to 7 th May (sample sizes of 12221 & 24523 giving a total of 36744). The best on the economy question asked in 1 st tranche – 12221 base.

5. What we did

6. Our polling adjustments 6 According to NRS Gender, Age, social grade, working status, region, tenure, cars, foreign holidays. Demographics Which party you most identify with Political ID 1-10 likelihood to vote Normalised for age On the register Alpha propensity model Turnout If you had to vote, who would you vote for? (don’t know/ refused) Squeeze

7. Late swing? 7 10-12 April29-30 April5 May5-6 MayGE Result (GB) Con33% 38% Lab33%34%33% 31% Lib Dem8% 9%10%8% SNP5%4% 5% UKIP15% 14% 13% Green5%4%6%5%4% Polled over 2 days to detect any late swing, but no evidence for one was found

8. Turnout weighting & squeeze 8 5-6 May (All who expressed intention to vote) 5-6 May (turnout weighting) 5-6 May (turnout weighting + squeeze FINAL) Con32%33% Lab35%34%33% Lib Dem9% 10% SNP4% UKIP13% 14% Green5% Voting intention adjusted according to declared likelihood to vote on a scale of 1 to 10, with responses of those saying they are more likely carrying greater weight Age-specific turnout weighting also introduced to compensate for younger voters overestimating their likelihood to vote in the election, based on historic data Propensity weights based on past voting behaviour Squeeze question

9. What we found

10. As shown by late VI poll, but also by recontact poll No evidence of late switchers 1.15-19 May online fieldwork. Base: 3036 10 5-6 May (last VI poll) 15–19 May (Recontact) GE Result (GB) Con33% 38% Lab33% 31% Lib Dem10%8% SNP4%5% UKIP14%15%13% Green5% 4%

11. The suspects

12. What are we doing? 12 More exacting demographic quotas beyond NRS weights Disabilities Public v private sector Education Sampling Asking likelihood to vote insufficient Developing propensity model Differential turnout weighting by demographic clusters Turnout weighting

13. Current Sampling 1.Online Fieldwork 5-7 May 2015 2.“Which party will you vote for in the General Election on May 7th?”. Base: All respondeonts expressing an intention to vote – Based on National Readership Survey (NRS) – Region – Sex – Age – Social Grade – Tenure – Working status – Cars – Foreign holiday 13 New trial Based on Government data (Census, ONS) – Region – Sex – Age – Social Grade – Tenure – Working status – Public sector – Cars – Foreign holiday – Disability – Education FINAL PUBLISHED PRE- ELECTION POLL With updated demographic weights GE Result 2015 (GB) Con33%35%38% Lab33%31% LD10%9%8% SNP4% 5% UKIP14% 13% Green5% 4%