Nigel Farage is the least popular political leader among first-time voters, who are over six times more likely to back the Greens than Ukip, according to an exclusive Opinium/Observer poll on the views of people aged 17 to 22.

The landmark survey of those who will be able to vote for the first time in a general election next May shows the new generation of voters to be pro-European, socially liberal, optimistic, hard-working and devoted to British institutions such as the monarchy.

There are more than 3 million young people – who grew up in an age of burgeoning social media – who will be eligible in less than five months’ time to vote for their national government for the first time. They are a key target group for all the political parties ahead of next year’s general election.

Strikingly, the new voters shun the anti-EU policies of Farage and Ukip. Only 3% of young people questioned said that they intended to vote for Ukip, compared with 19% among voters of all ages.

Just 13% said they approved of Farage, against 64% who said they disapproved, giving him a net approval rating of -51%, worse than that of Lib Dem Nick Clegg, who scores -44%.

Facebook Twitter Pinterest Nigel Farage is the least popular party leader among young voters. Photograph: Tom Pullen/REX

Some 62% of young people said they believed the UK’s membership of the EU was a good thing, with only 14% disagreeing. Even among young Conservative-inclined voters, 57% thought EU membership to be positive.

Support for the EU was even stronger when first-time voters were asked how they would vote in an in/out referendum on the UK’s continued membership – promised by David Cameron by the end of 2017, if the Tories win the election. Some 67% said they would vote to stay in, while only 19% would vote to leave. Among all voters, the split is close to 50-50.

The findings suggest that a more strident anti-EU message from the Conservatives – to counter the threat of Ukip – would drive away more young first-time voters.

Opinium/Observer poll young voters - full graphic here

The poll shows Labour has a comfortable 15% lead over the Tories in this age group, compared with a lead in low single figures in most recent surveys of the entire electorate. Among first-time voters who are likely to go to the ballot box and who selected a preferred party, Labour is on 41%, the Conservatives 26%, the Greens 19% and the Liberal Democrats 6%.

At the 2010 election, 30% of people aged 18 to 24 who voted chose the Lib Dems, 30% the Tories and 31% Labour.

Even among young voters, there are serious doubts about Ed Miliband as a leader. Just 24% of all the first-timers surveyed said they approved of his leadership, against 42% who disapproved. Cameron fared better, with 35% for and 41% against.

Traditionally, young people have been the least likely to vote in general elections, meaning that the main parties have often focused on older groups. Next May, however, all the main parties will be targeting young people online, trying to engage them directly through social media sites.

The survey found that 92% of first-time voters have accounts with Facebook or have used it in the last year; 53% had signed a petition online; but only 13% had written to an MP, councillor or other elected official.