In announcing the snap election, Theresa May set out her desire to create a “more united” country in the aftermath of last year’s referendum. But as the campaign begins, new YouGov analysis of over 12,000 people shows the demographic dividing lines of British voters.

Although every voter is an individual, this data shows how demographics relate to electoral behaviour. These divides will shape the next few weeks – from the seats the parties target to the key messages they use. Over the course of the campaign we will be monitoring not only the “headline” voting intention numbers, but also the many different types of voters that make up the electorate.

Class: No longer a good predictor of voting behaviour

“Class” used to be central to understanding British politics. The Conservatives, to all intents and purposes, were the party of the middle class and Labour that of the workers. The dividing lines were so distinct that you could predict, with a reasonable degree of accuracy, how someone would vote just by knowing their social grade. For example, at the 1992 election the Conservatives led Labour among ABC1 (middle-class) voters by about 30 percentage points, while Labour was leading among C2DE (working-class) voters by around 10 points.

But today, class would tell you little more about a person’s voting intention than looking at their horoscope or reading their palm. As this campaign starts, the Conservatives hold a 22 per cent lead among middle-class voters and a 17-point lead among working-class voters.

Age: The new dividing line in British politics

In electoral terms, age is the new class. The starkest way to show this is to note that Labour is 19 points ahead when it comes to 18-to-24-year-olds, and the Conservatives are ahead by 49 points among the over-65s. Our analysis suggests that the current tipping point – which is to say, the age at which voters are more likely to favour the Conservatives over Labour – is 34.

In fact, for every ten years older a voter gets, their chance of voting Tory increases by roughly 8 per cent and the chance of them voting Labour decreases by 6 per cent. This age divide could create further problems for Labour on 8 June. Age is also a big driver of turnout, older people being far more likely to vote than young people. Buy it’s too early to tell the exact impact this could have on the final result.

Gender: The Conservatives’ non-existent “women problem”

Before the last election David Cameron was sometimes described as having a “woman problem”. Our research at the time showed this narrative wasn’t quite accurate. While it was true that the Conservatives were doing slightly better among young men than young women, they were also doing slightly better among older women than older men.

However, these two things cancelled each other out, with the result that ultimately, the Conservatives polled about the same among both men and women. Going into the 2017 election, women are, if anything, slightly more likely overall (by 3 percentage points) to vote Tory.

Labour has a large gender gap among younger voters. The party receives 42 per cent of the under-40 women’s vote, compared to just 32 per cent among men of the same age – a gap of 10 points. However, among older voters this disappears almost completely. When you just look at the over-40s, the gap is just 2 points – with 21 per cent of women and 19 per cent of men of that age saying they will vote Labour.

With both of the main parties now performing better among women overall, it’s the other parties that are balancing this out by polling better among men. Ukip has the support of more men than women (by 2 percentage points), while the gender gap is 3 points for the Lib Dems.

Education: The higher the qualification, the higher Labour’s vote share

Besides age, education has become one of the critical electoral demographic dividing lines. We saw it was a huge factor in the EU referendum campaign and, after the last general election, we made sure we accounted for qualifications in our methodology. This election will be no different. While the Conservatives lead in all educational groupings, their vote share decreases for every extra qualification a voter has, while the Labour and Lib Dem vote share increases.

Among those with no formal qualifications, the Conservatives lead by 35 points. But when it comes to those with a degree, the Tory lead falls to 8 points. Education also shapes other parties’ vote shares. Ukip similarly struggles among highly educated voters, polling four times higher among those with no formal qualifications than those with a degree.

Income: Labour’s tax increase won’t affect many Labour voters

For Labour, John McDonnell, the shadow chancellor, has already made income part of this campaign by labelling those who earn above £70,000 a year as “rich” and hinting that they may face tax rises. One of the reasons for the policy might be that the party has very few votes to lose among those in this income bracket.

Among those earning over £70,000 a year, Labour is in third place, with just 11 per cent support. The Conservatives pick up 60 per cent of this group’s support and the Lib Dems also perform well, getting almost a fifth (19 per cent) of their votes.

But although the Conservatives are still the party of the rich, Labour is no longer the party of the poor. They are 13 points behind among those with a personal income of under £20,000 a year, though it is worth noting that this group will also include many retired people who are poor in terms of income but rich in assets.

Chris Curtis is a politics researcher at YouGov.