The left will never win over the middle class, or so the argument used to go: now the left is accused of winning over too many middle-class voters. Four in 10 British voters opted for Labour’s most leftwing manifesto since 1983. That socialist ideas could attract such support – and leave Jeremy Corbyn’s Labour with a “straightforward” path to victory, according to psephologist John Curtice – is in defiance of political gravity. At least, that’s the belief of those who base their entire political creed on the idea that leftwing policies will invite only electoral Armageddon. And so arrives the argument that the Labour voters who delivered a historic upset were the wrong voters: too affluent, too middle class. But socialism offers emancipation for middle class and working class alike: indeed, that is Labour’s only possible winning electoral coalition.

'It's bloody brilliant!' Michael Eavis on bringing Jeremy Corbyn to Glastonbury Read more

Corbyn’s rapturous reception at Glastonbury is offered as evidence that it is pampered middle-class hipsters powering Labour’s surge. “This would be the political force quoting Shelley to people who paid £243 per ticket for the privilege,” wrote one commentator. “Irony is dead.” Social media abounds with mockery about the affluent crowd cheering on Corbyn’s polemic against injustice. “It is populism for the middle classes,” is one summary of Corbynism. A “virtue-signalling middle-class romantic” is another description of the Labour leader. Labour is now the party of the middle class, declares the Spectator magazine.

Nearly 13 million people voted for Labour just over two weeks ago: few of these are likely to be well-heeled bohemian radicals. When it comes to Glastonbury, the criticisms are based on a very patronising view indeed of working-class Britain. The people I grew up with in Stockport prided themselves on saving up for nice things: whether it was designer clothes, or sun-soaked holidays, or indeed music festivals. Many of Glastonbury’s crowd save up all year to afford a ticket, because the festival is one of the highlights of their calendar.

In any case, the polling is very clear indeed. In the electorate as a whole, support for Corbyn’s Labour party is at its highest among young working-class people. While 52% of middle-class professionals aged under 35 opted for the Labour party, 70% of younger people in the “DE” social category – those classed by pollsters as most working class – voted for Corbyn’s party. One of the most effective mobilisers of young Labour support in the election campaign was Grime4Corbyn, reaching out to overwhelmingly young working-class people, many from minority backgrounds.

Overall, Labour won a significantly higher chunk of working-class support compared to just two years ago. Among those classed as DE – a category that includes semi-skilled and unskilled manual workers – Labour had a nine-point lead over the Tories. Sure, Ukip’s collapse in particular infused the Tory voter share with older working-class support, and that remains a challenge for Labour to overcome. Overall, the Tories ended up with a four-point lead among skilled workers. But Labour still won nine points more support among those voters than they managed to get in 2015.

Labour’s electoral coalition brings together middle-class and working-class voters alike. It wasn’t enough to win: but Britain’s electoral map is now littered with marginal constituencies that, with the right approach, can become Labour gains when Britain next marches to the polls. That’s how the party won seats it has never triumphed in before, such as Kensington and Canterbury. While the left used to be critiqued for attracting too narrow a support base, Labour’s coalition is now accused of being too expansive. “Corbyn’s coalition of Kensington and Doncaster is unsustainable over the long term,” says politics academic Matthew Goodwin. “At some point, one side will not get what they want.” The left is accused of either being incapable of winning beyond Labour’s core working-class constituency, or it is – as now – denounced for winning over too many affluent voters. It is either betraying those the party depends on the most by failing to win more well-off constituencies it needs to gain office, or it has constructed too broad a coalition and is therefore doomed.

Labour took the Battersea seat after promising to ask high earners to pay more tax

A Labour party led by its left flank is indeed potentially on the cusp of power, although a shambolic Tory government desperate to prevent such an outcome will hang on for as long as it can. Only a coalition of working-class and middle-class voters will make a majority Labour government possible. Both middle-class and working-class voters depend on public services, such as a comprehensive education system and the NHS. Both desire well-paid secure jobs, not just for themselves, but for their children, too. Both wish to be a rid of a housing crisis which too often robs their children of affordable, comfortable, and indeed safe homes. Both want decent pensions. Both suffer the consequences of utilities, such as the rail system, being run by profiteers with little interest in the needs of consumers. Both want affordable childcare so they don’t have to make difficult choices about careers and families. Both will benefit from the most well-off in society paying a bit more in tax to invest in creaking infrastructure, services, education, housing and jobs.

The dominant media narrative was that Labour suffered its defeat in 2015 because it was simply too leftwing. Take Battersea in London: some claimed Labour’s failure to win the seat in 2015 was down the party’s “mansion tax” policy. This time round, Labour took the seat after promising to ask high earners to pay more tax. Middle-class people were not deterred by a commitment to ask those earning more than £80,000 a year to contribute more. Yes, Labour must win over more older working-class voters, as well as encouraging more younger Britons to vote. Yet this election shows that socialism can convince both middle-class and working-class voters alike. Critics of such a Labour approach will always shift the goalposts, claiming that the left either wins too little middle-class support or too much. Democratic socialism relies on a coalition of working-class and middle-class Britain. The support of middle-class Britons is not symptomatic of failure: it is a sign of success. Socialism won’t just transform the life chances of working-class Britain: it has an inspiring vision for the middle class, too.