Photo: Getty

For pollsters, analysts, and politicos, one of the most important issues ahead of May’s general election is the Ukip effect.

How many people will vote for the party, and what impact will they have? We can get an idea by studying all our polls from January (Populus publish two polls a week, on Mondays and Fridays).

Our data involves more than 16,000 interviews, and puts Ukip on 13.2 per cent. Support seems fairly stable: the party was on 12.6 per cent in January 2014 and 13.4 per cent in June 2014 after the European elections. Support is not, however, consistent across different types of voters.

All parties attract more support from some groups in society than others, and Ukip is no different. We’ve used the same techniques we used last week for the Green Party to display these differences via an Index.

Ukip support seems to decrease with educational attainment.

In the graph below, an Index score of 100 is average, showing the group is no more or less likely than average to vote Ukip. Scores above 100 indicate a greater level of support for Ukip, and scores below 100 a lower than average level of support.

It is clear that Ukippers are more likely to be male and to be older. Those aged 45 or older – and particularly those aged 65 and above – are more likely than average to support Ukip. Geographically, support for Ukip is higher in Eastern England, Yorkshire & Humberside, and the Midlands. Support is noticeably weaker in Scotland, as well as in London.

And, as the graphic below shows, Ukip support is substantially weaker among public sector workers, private renters, those from a non-white ethnic background, individuals still in full time education, and those with a higher university degree.

Indeed Ukip support seems to decrease with educational attainment – there is a spike in support among those with secondary education. Other groups that ‘over-perform’ include retirees, renters of council or housing association homes, and individuals living in rural areas.

Many of these characteristics contrast with those of Green Party supporters – another group that has become more popular in recent times (but only by about half as much). Ukip voters are likely to be older, Green voters younger. Ukippers are more likely to be men, Greens more likely to be women. Ukip are more likely to be retired, and Greens more likely to be students.

While the two parties have both been described as offering an alternative to the three main Westminster parties, the demographics of their supporters show how they are the non-identical twins of the anti-Westminster mood.

Studying how Ukippers voted in 2010 – something May2015 has often done – demonstrates why the party represents a threat to all Westminster parties, but particularly the Tories. Just 14 per cent of current Ukippers voted Ukip in 2010.

That leaves a very large proportion of voters moving from other parties to Ukip, and the largest source of these new Kippers are ex-Tories.

Ukip undoubtedly attracts supporters from all walks of life – a party polling strongly just three months before a general election must – but our Ukip Index illustrates the types of voters most likely to have been won over.

It also allows us to identify a typical supporter – likely to be male, retired, a former Conservative voter, finished education at the end of secondary school, and perhaps living somewhere in Eastern England. A bit like this guy.

Laurence Stellings is an associate director at Populus Polls, on whose site this post originally appeared.