Do “tree huggers” have a place in Keir Starmer’s Labour party? After the party’s failure to take Boris Johnson’s former seat of Uxbridge and South Ruislip in Thursday’s byelection, the Labour leader’s commitment to green policies has been called into question. Earlier this month, the Sunday Times reported that Starmer has grown so frustrated with green policies – which the Tories are accused of having “weaponised” to spark a culture war over the environment – that he declared: “I hate tree huggers.” Labour insiders rushed to say this was not true, and pointed to the recent launch of a number of green measures, including a halt to new North Sea oil and gas licences; decarbonising the energy system by 2030; and £28bn a year for green investment, though this was postponed to the second half of the next parliament instead of the start. The Uxbridge and South Ruislip byelection, which Labour failed to win by just 495 votes, has revived concerns. Uxbridge is one of the most car-dependent constituencies in the country, and Labour’s London mayor Sadiq Khan is about to introduce an extension to the ultra-low emissions zone (Ulez) that would penalise the area’s most polluting vehicles in an attempt to clean up the capital’s filthy air. Starmer blamed Labour’s failure to take the seat it was keenly targeting on the anti-pollution policy. He told journalists: “Ulez was the reason we didn’t win there yesterday. We know that. We heard that on the doors. And we’ve all got to reflect on that, including the mayor.” Asked what “reflect” meant and whether Ulez should be scrapped, Starmer refused to defend the policy. He said: “We’ve got to look at the result. The mayor needs to reflect. And it’s too early to say what should happen next.” Tom Burke, the co-founder of the green thinktank E3G, predicted that those within Labour who are antagonistic to green measures will seize this moment. He said: “There will be pressure inside Labour – some people will take fright from this.” Some trade unions have deep reservations about the transition to a low-carbon economy, and some in the party are fearful over Tory attacks on climate policies. But Burke warned that Starmer should not listen to these concerns. He said: “They should be very careful in generalising from this to climate policy more generally. What Starmer should do is not attack his own side, but communicate far more effectively what the consequences will be of climate policy failure. That’s what’s missing from this debate.” Insiders said there would be no change to Labour’s green stance. A Labour source said that green policies such as ramping up renewable energy and home insulation were the way to bring down soaring bills. The source added: “It’s full steam ahead on policies that tackle the climate crisis and the cost of living, as they can only be tackled together – that’s the only way.” Doug Parr, the chief scientist and policy director at Greenpeace UK, said that is the right response. He explained: “The worst and most regressive take would be that this shows green policy is unpopular. We know that people are crying out for action on climate and nature, and it needs visionary and fair policy to make it happen. “Far from retreating, they need to go further and faster and ensure that measures are in place for ensuring the burden of change does not fall on those with the least resources.” The local problem of the Ulez is also likely to dissipate. Khan’s team said it would still come into force at the end of August, and small businesses and those receiving child benefit will get financial help to scrap the most polluting vehicles. They hope that the onset of the scheme will dispel damaging myths over who will be affected, and help people to realise the benefits of cleaner air. What is clear is that Starmer can expect many more attacks from the Tories on green grounds. Labour insiders alleged that the Tory campaign in Uxbridge was fought with “dirty tricks”, with voters being misled over the impact of Ulez. They say many voters were given the mistaken impression that they would lose the right to use their cars, when in fact only one in 10 people will be affected. In one case, a driver of a Tesla electric car berated Labour canvassers on the doorstep, fearing he would face restrictions, based on Tory campaigning. It seems unlikely there will be any letup in the Tory climate culture war, however, now that the Uxbridge campaign has borne such fruit. Grant Shapps, the energy secretary, has been stepping up his attacks on Labour, branding the party “the political wing of Just Stop Oil”. He wrote to Starmer this week to demand Labour pay compensation for damage caused by the group’s protesters. Burke was scathing about these tactics. He said: “Whenever you see politicians being rude like this, it means they really don’t know what to say about how to square the divisions inside their own party on the issue. These Tory attacks are increasingly ridiculous, and they are misleading themselves about what the public think.”