It’s the mood music that matters most. The budget needs to sing “Here comes the sun” after too many grey months of grim prognosis. That hefty red book needs to tell a story of how this long and winding road leads us out of the despondency of austerity. There’s no need for fantastical “world-beating” boosterism but even so, the chancellor needs to give us a tune to carry people along with her. The Tories and their press risk running out of Halloween frighteners by the time she gets to her feet on Wednesday, already catastrophising: “Starmer has put the final nail in the coffin for British aspiration,” (the Telegraph), “Class war” against “middle Britain” (the Daily Mail), and Rachel Reeves’s “web of lies” concealing her “dystopian plan for Britain”. On a table just outside Reeves’s office the day’s papers are laid out, headlines howling at her whenever she walks past. I suggested to an aide they be covered up to stop them getting to her. This is the same rightwing press that misleads the Tories into selecting another “small state” leader and that, with zero self-reflection on their party’s worst ever defeat, ignores the curious fact that a majority of Sun, Express, Mail, Telegraph and Times readers voted Labour rather than Tory. Patriotic? They try to spook the bond markets in advance, but there’s no sign the steady-as-she-goes chancellor is herself easily spooked. Though the government isn’t popular, Margaret Thatcher did far worse in the early days of her prime ministership. Time is on Labour’s side, as Keir Starmer said on Monday, reassuring voters that “better days are ahead”. People voted for capital investment in crumbling schools and hospitals, in energy, housing, rail and roads, and tax revenue to rescue every service from the cuts the last government planned. This is the moment to remind voters not of the burden of tax, but of its great social value: the choice is tax or decline. The confected row over who counts as “working people” could have been stopped dead had Labour let ministers make the simple distinction between “earned” and “unearned” income. Laura Kuenssberg, goading the education secretary, Bridget Phillipson, pleaded the cause of hard-working landlords who “scrimped and saved to buy a couple of rental properties”. Yet only about 7% of people let out a property – that’s the same as the percentage of British pupils who attend private schools. No wonder the UK is so ill-informed about the true distribution of wealth and earnings when extremes of privilege such as this are misrepresented as ordinary. The reason the mood music matters so much is that most voters understand very little of the budget’s language or numbers, as the tax expert Dan Neidle has recently found. The majority rightly think the state spends most on healthcare, but after that it gets alarming: they think asylum and migrants get the second-highest spending, when that’s less than 1%. They think MPs’ expenses are the third-highest spend, but it’s 0.01%. How easily demagogues can trade on ignorance, thanks to the wildly disproportionate emphasis the media gives some issues. Most people understand shockingly little of their own finances, according to the Centre for Economics and Business Research. Three-quarters of voters fall below the most basic level of financial literacy compared with equivalent countries, stumped by many simple questions. They can’t guess how much £100 would yield after five years in a savings account at 2%, for instance. If inflation is 4%, most don’t know whether those savings at 2% will buy them more, less or the same after two years. None of the 10 questions were harder than those, an indictment of a maths curriculum that fails to impart the everyday knowledge people need in life – let alone enough to help them make informed political decisions. So on budget day most voters are undefended against a blast of malevolent misrepresentation. How can people judge taxes when most don’t know that higher tax is only charged on the part of their income that is above the higher threshold? Neidle worries that some people turn down a small wage rise because they wrongly assume it will tip their entire income into the upper tax bracket. The answer? Education, education, education, plus more prominence for independent fact checkers such as Full Fact. On the extra national insurance contributions for employers, YouGov finds a small majority of people are opposed to these tax rises, but those attitudes shift dramatically when people are told the proceeds of this rise would go to the NHS. It might be tempting to assign taxes for popular purposes on budget day, but that kind of hypothecation is a primrose path to perdition, leaving less popular causes out in the cold. Too few would choose to see their taxes spent on defence, benefits, prisons or foreign aid. The proposed tax rises that people do support are interesting: raising betting tax comes top, capital gains second – and, joint third, they back taxing private schools and banks. All the Tory hullabaloo about Labour’s wicked class warfare imposing VAT on private schools seems to have found little popular resonance. In a sea of ignorance and deliberate misinformation, the country relies on a chancellor who will tax and spend according to longer-term national need. Promising her budget will match the “greatest economic moments in Labour history”, Reeves needs to set those plans to political music that people can hear beyond the numbers, with a strong theme tune of reasons to be cheerful. Polly Toynbee is a Guardian columnist