Individual pollsIn April 2014, TNS found 52% of respondents in favour of the UK renegotiating its EU membership. The poll also found a perception that the UK is unfairly treated during EU negotiations. Those in favour of EU membership cite trade benefits as the main reason for support, while those who wish to leave often point to immigration and interference in the justice system rather than to any economic benefits of leaving. This suggests, argued TNS, ‘that making the case for EU membership based on trade benefits is unlikely to sway those who favour leaving due to fear of immigration’ (see Public have low confidence in UK government’s ability to renegotiate EU membership).Marking 100 days to the Referendum, TNS released results on 17 March showing ‘36% would remain, 36% would leave and 28% didn’t know how they would vote’ (see As the campaign enters its final hundred days, both sides are yet to see a breakthrough).On 5 April, TNS found a Large preference for Scotland remaining in the EU – [although] many still unsure.On 13 April, TNS found ‘both campaigns holding steady at 35% apiece and failing to win over undecided voters, who also remain steady at 30%.’ Among undecided voters, 27% were leaning to Remain and 15% to Leave 15%, while 57% said they didn’t know how they’d vote (see Still no breakthrough for referendum campaigns).Results published on 17 May showed Remain on 38 (-1), Leave on 41% (+5), and Undecided at 21% (-5; see One in five voters still undecided on EU Referendum).According to a February 2015 ComRes / New Direction poll across nine EU countries, only 19% of UK adults are satisfied with the EU in its current form. ComRes said that the poll ‘shows that those calling for EU reform now represent the mainstream view’. In December 2015, a survey on behalf of Open Europe found that 56% of respondents favouring ‘remain’ and 35% preferring ‘leave’. The 21 point lead had changed little since September 2015 said ComRes.On 15 February 2016, a ComRes poll for ITV News found that the lead for ‘remain’ has narrowed to eight points (49% for stay, 41% for leave). A poll published on 23 March, again for ITV News, showed ‘remain’ leading by 48% to 41%. The poll also found ‘that David Cameron is the most important politician in deciding how people will vote at the referendum.’On 18 April, a ComRes Poll of general public and Sun readers about the EU referendum found that ‘45% say they would vote to stay if the referendum were tomorrow, compared to 38% who would vote to leave.’A 19 May poll saw 52% saying they would vote for Remain, compared to 41% opting for Leave and 7% undecided (see ITV News / Daily Mail EU Referendum Poll May 2016).A September 2015 poll by YouGov found that 38% supported staying in the EU and 40% favoured leaving. Asked how they would vote if David Cameron obtained new terms for the UK and recommended staying in the EU, 47% said they would vote to stay and 29% to leave.In January 2016, YouGov polled opinion amongst businesses. Overall, 47% favoured staying in the EU and 42% would rather leave. YouGov compared that to its December 2015 poll of the general public, which found 41% favouring remain and 42% preferring to leave (see YouGov Europe page).On 5 March, YouGov said that ‘Remain have a small lead and are supported by the fundamentals, but referendum polls this far out are a poor guide’ (40% remain, 37% leave, 23% don’t know or wouldn’t vote: The YouGov view).A YouGov poll on 6 April found a one point lead for Remain over Leave (39% to 38%), with no change among those who don’t know and won’t vote (18% and 5% respectively; see Remain lead at one in EU referendum).Later in April, YouGov found that ‘Most groups are expected not to benefit from Brexit – but small business owners, the unemployed and those on low wages are among the groups expected to be harmed least’ (see Brexit seen as least bad for the working class). Small businesses had a Brexit score of +1; ethnic minorites scored -25.On 18 May, YouGov found Remain on 44% and Leave on 40%, with 12% undecided and 3% not intending to vote (see EU referendum: Remain lead at four).September 2015 poll by Survation found the first majority in favour of leaving the EU. Responding to the revised ballot paper question, 43% said they would vote to leave; 40% to stay. Excluding undecided voters, the results were 51% to leave and 49% to stay. In November 2015, Survation conducted an online poll on behalf of Leave.EU, which showed 40% of respondents wanting to leave, 42% to remain, and 18% undecided.Survation’s first EU Referendum poll of 2016 (19 January) on behalf of the Mail on Sunday, found ‘leave’ on 42%, ‘remain’ on 38%, and 21% of voters undecided (see Survation EU Referendum search results page).A Survation poll published on 27 April showed Remainers on 45% (-1), Leavers on 38% (+3), and the Undecideds on 17% (-2).A month later, on 25 May, polling found Remain at 44% (-1), Leave at 38%, and undecideds on 18% (+1).In mid-November 2015, ORB International found 52% wanting to leave the EU and 48% to remain. ORB said that was the first time in six months that it had found amajority in favour of leaving (see ORB news item). In January, ORB found 52% of those polled would vote ‘remain’ and 48% would vote ‘leave’. The poll found Conservative voters split 50-50 on the issue (see UK attitudes towards … Brexit).In February, ORB found 52% for leave and 48% for remain, and noted: ‘men are more likely to turnout than women, and as with many general elections older people are currently showing more interest in voting’.An ORB Daily Telegraph poll (20-24 April) showed ‘51% of definite voters will vote to remain, 46% would vote to leave, and 3% are undecided.’For 18-22 May, results put 58% for Remain and 38% for Leave, with 4% undecided.On 29 January 2016, Ipsos MORI reported ‘remain’ still ahead, although with a narrower lead: 55% for remain; 36% to leave; overall a 3.5 point swing to leave (see Ipsos MORI Political Monitor January 2016).Based on fieldwork done in November and December 2015, a Survey of MPs on the European Union published on 1 February 2016 found that 50% of MPs would vote for remain regardless of any UK deal, and 35% would decide based on the outcome of negotiations. In party terms, 87% of Labour MPs said they would vote to remain, as would 11% of Conservative MPs. 20% of Conservative MPs said they would vote to leave regardless of any deal.The Ipsos MORI Political Monitor February 2016 found little change in views towards Europe, with 54% of those polled preferring to remain (down 1 point) and 36% to leave (no change).On 4 March, the Economist/ Ipsos MORI February 2016 Issues Index recorded concern about the EU at its highest level in 13 years, with 20% of respondents mentioning it ‘as amongst the most important issues facing Britain’.According to the Ipsos MORI Research Highlights March 2016 ‘In 1975, at the last referendum on the issue, only 65% bothered voting. This time turnout is likely to be lower still, which may help the ‘Brexit’ supporters. Even so, 62% of the public currently expect the country will vote to stay IN.’In the Ipsos MORI Political Monitor March 2016 (published on 29 March), half of those polled said that David Cameron should resign as Prime Minister if there is a vote to leave the EU.On 26 April, the Economist/ Ipsos MORI April 2016 Issues Index showed ‘a further increase in the importance of the EU as an issue facing Britain. Three in ten (30%) of the public now mention it as one of the most important issues facing Britain, the highest recorded level since December 1999. Conservative voters (43%), those living in the south east of England (37%) and those aged 55 and over (43%) are particularly likely to feel this is a big issue.’The Ipsos MORI Political Monitor May 2016 showed ‘that on balance Britons believe the economy would be better off in the long term if Britain left the European Union yet likely be worse off in the years immediately following Brexit.’ 55% said they would vote Remain, 37% Leave and 8% declared themselves undecided. Polls of polls, trackers, analysisThe Telegraph publishes an EU referendum poll tracker which it updates monthly. In November 2015, 52% of respondents wanted to leave and 48% to stay. That was a significant shift from June 2015, when the figures were 61% for staying and 27% for leaving. The figures for December 2015 were ‘leave’ 41% and ‘remain’ 42%. Figures for 16 February showed 51% to stay and 49% to leave. On 21 March, the poll of polls showed 51% for remain and 49% for leave. In early April, the two sides were both on 50%. On 25 April, Remain had 51% and Leave 49%. A month later, on 25 May, Remain was on 53% and Leave on 47%.Polling company ICM publishes a weekly EU Referendum Tracker which in mid-November 2015 showed 19% undecided, 38% wanting to leave, and 43% saying they would vote to remain in the EU. At the end of January 2016, the Tracker showed both sides on 41%, and on 18 February showed the ‘Remain’ camp leading by 43% to 39% (or 52% to 48% once undecided respondents were excluded). On 22 March, that picture had changed, with ‘43% expressing support for Leave compared to 41% for Remain In’. On 12 April, Remain were on 42% and Leave on 45%, with 12% of respondents undecided. Excluding the undecideds put Leave ahead by 52% to 48%. On 24 May, results were Remain on 47% (telephone poll) and 43% (online); Leave 39% (telephone) and 47% (online); and don’t knows on 14% and 10% (see EU referendum page).The UKPollingReport website offers comment and analysis on a range of polls (e.g. Some more EU Referendum polling data, 16 November 2015) and includes a summary of EU Membership Referendum voting intentions.What Europe Thinks is compiled by the Centre for Comparative European Survey Data (CCESD) at London Metropolitan University. It ‘includes all major comparative European Union social surveys, spanning over 40 years with 100,000s of questions — a unique source to put Great Britain in perspective in the lead into the EU referendum.’What UK Thinks: EU provides ‘impartial, up-to-date information on public attitudes to the European Union as the UK prepares to hold a referendum on its membership’. The site is run by NatCen Social Research, which is also responsible for the British Social Attitudes surveys. What UK Thinks: EU includes an EU Referendum Poll of Polls. From mid- to end-November 2015, it found an average of 51% in favour of remaining and 49% wanting to leave. Analysis of six polls undertaken between 8 and 24 January 2016 showed both sides on 50%. Polls conducted between 3 and 16 February showed a 51% to 49% advantage for ‘Remain’. Those figures were the same for polls taken between 4 and 20 March. For the period 24 March to 10 April, the polls averaged 50-50. Six polls from 15-26 April averaged 54% for Remain and 46% for Leave.For the period 15-26 April, six polls averaged 53% for Remain and 47% for Leave.On 8 April, Professor John Curtice commented on the closeness of the results, saying: ‘Poll after poll finds that most voters believe that being in the EU results in too much immigration and undermines Britain’s sovereignty. At the same time, most voters are also inclined to the view that leaving the EU would be harmful to the economy and poses something of a risk …’The 32nd report in the British Social Attitudes series includes a section on Britain and Europe, as well as an insight into the social and political attitudes of UKIP supporters. Excerpts from the 33rd report look at How deeply does Britain’s Euroscepticism run? and at Brexit: What will it mean for Britain?Betting oddsIn June 2015, bookmakers William Hill were giving odds of 2/9 on the UK voting to remain in the EU, and 3/1 on a vote to leave; in early December, the odds were 4/9 for staying and 7/4 for leaving; and in late January 2016 were 4/11 to remain and 2/1 to leave. On 20 February, odds were 2/7 to remain and 5/2 to leave. On 12 April, odds were 2/5 to stay and 15/8 to leave. Odds on 27 May were 1/6 to remain and 4/1 to leave.The Oddschecker website provides Brexit Referendum Betting Odds from a range of sources, while PoliticalBetting.com offers analysis as well as odds.