It can’t be easy being Barbie. As if life wasn’t tough enough for an ageing doll with a decorative dimwit for a boyfriend, this week she suffered the indignity of being dragged into a byelection. Or more precisely, her bright pink classic Corvette did. In easily the most excruciating moment of an already awkward attempt to cling on to Boris Johnson’s old Uxbridge seat, Tory HQ briefly tried to enliven its main line of attack by suggesting to friendly newspapers that if Barbie for some unexplained reason rocked up in the suburbs, she might have to pay £12.50 for breaching mayor Sadiq Khan’s ultra-low emission zone (Ulez), due to be extended to the capital’s outer fringes from August. At the time of writing, the voters’ verdict on this one is still hotly awaited. But whatever the outcome, hiding behind a dolly feels like the kind of political low point nobody gets over in a hurry. The idea that what the Spectator hopefully calls a “great motorist rebellion” against the tree-hugging classes could somehow save the Tories from obliteration at the next general election feels like clutching at straws in a hurricane. For all the sound, fury and mad conspiracy theories flying about over low-traffic neighbourhoods (LTNs), which are aimed at stopping motorists cutting through side streets, anti-LTN candidates failed to unseat Labour councillors in Oxford in byelections this spring. However irritating the commuting classes might find Just Stop Oil, most are angrier about the state of their mortgages. All that said, there’s a reason Conservatives seem increasingly keen to play the embattled motorist card all the way through to the next election, if only to limit the scale of their expected losses. For all that Europe is now burning right before our eyes, going green is undoubtedly a harder sell in the middle of a cost of living crisis. Seven years ago, YouGov found overwhelming support for curbing pollution in cities, emboldening councils to push ahead with planning clean air zones across the country, from Bath and Bristol to Sheffield and Aberdeen. We’d had enough of sweltering in traffic jams and wondering guiltily about all the fumes children must be inhaling as they walked to school; we accepted there was a price to be paid. But is that enthusiasm now waning? Polling shows a narrow majority of Londoners still favour expanding the Ulez, but it’s markedly more popular among middle-class professionals than low earners who can’t afford to trade in spluttering old diesels. In Manchester, government plans for a clean air zone were put on hold last year after a furious backlash: the city’s Labour mayor, Andy Burnham, led the attack, arguing that instead of pricing struggling van and taxi drivers off the road if they couldn’t afford to trade in their old polluting vehicles, they should be given financial help to switch. A recent poll for the secondhand car site Carwow found drivers still think pollution should be tackled in principle, but in practice 59% said now was not the time – a line echoed by Labour’s candidate in Uxbridge, Danny Beales, who said he’d heard “heart-wrenching stories” from locals who couldn’t afford new cars. Keir Starmer has notably struggled to muster a full-throated defence of the Ulez in interviews, although it catches only one in five London cars and there’s a £110m scrappage scheme to help drivers on low incomes upgrade. Some of the resistance is undoubtedly down to the Mr Toad tendency, enraged by any attempt to prise their hands off the steering wheel. (Though clean air zones aren’t strictly speaking designed to force motorists on to the bus, by painting driving as a filthy, antisocial habit, they undoubtedly offer a hefty nudge in that direction). But there remains an awkward grain of truth in the argument that – ironically, much like air pollution itself, which is most lethal to the poorest living on busy arterial roads – clean air zones are toughest on people who can least afford to comply. That means delivery drivers buzzing around on cheap mopeds; white van drivers; shift workers dreading the day their knackered old banger fails its final MOT, because it’s the only way to get home safely in the middle of the night; and also small high street businesses struggling to stay afloat, worried this might be the final death knell for customers driving into town. None of this changes the fact that pollution kills, cities need to wean themselves off cars, and the climate crisis poses an existential threat. But if going green costs money that not everyone has, then ultimately there are only two plausible political responses. The first is utterly unconscionable, since it means reneging on net zero. The second is to find the money for a genuinely fair transition, and fast. This isn’t just about Ulez. There are some alarmingly big bills looming for millions of households in the name of saving the planet, and however clearly people might see the moral case for getting rid of their gas boiler or their old petrol car at a time when forest fires are ravaging Greece and flash floods are hitting Spain, money is money. If you genuinely can’t afford to switch, few things are more alienating than being made to feel guilty about that by people shocked at how hot it was on the beach in Sicily this year. So far, net zero targets have relied heavily on the eco-conscious middle classes willingly absorbing the upfront costs of doing the right thing. But for drivers who haven’t yet gone electric, the rocketing cost of living is creating a powerful incentive to hang on to your old car for a year or two longer. Heat pump sales are still worrying low, suggesting homeowners are either burying their heads in the sand or hanging back to see whether they’re really going to be forced to rip out the central heating. There’s a danger of progress stalling just when it needs to accelerate. Unsurprisingly, most politicians are keener to talk about shiny new green jobs or cheap solar energy than about where they’ll raise the money to fund new scrappage schemes and grants. But somehow we must find ways to spread the collective burden of what we all know needs to be done. For when the collective good collides with hard-headed self-interest, that’s when the left is perennially in danger of coming unstuck. When times are tough, people start listening to the devil whispering on their shoulder: sure, someone has to save the planet, but does that someone really have to be me? The biggest hurdle for Labour in power will be to show that for once, we really are all in this particular existential fight together. Gaby Hinsliff is a Guardian columnist