Candidates in 21 council areas in Thursday’s local elections have pledged to roll back low-traffic neighbourhoods (LTNs) or clean air zones, a Guardian analysis of Facebook ad library data has found. Most of the adverts – 136 out of 164 analysed – were placed by Tory candidates, putting local Conservative parties at odds with central government which has encouraged councils to adopt clean air zones and LTNs, and funded the schemes. Labour candidates have placed six adverts criticising a clean air zone or LTN, while Liberal Democrats have placed three and independent candidates have placed 19. Clean air zones restrict the movement of older, more polluting vehicles to improve air quality, while low-traffic neighbourhoods are areas in which motor traffic is prevented from using residential streets as cut-throughs. If clean air zones were implemented across eight UK cities, they would deliver, on average, an 18% reduction in nitrogen dioxide, a harmful pollutant, according to research by CBI Economics. However, these schemes have often divided opinion, and ads that oppose a clean air zone (CAZ) or LTN have been viewed 613,000 times on Facebook since the start of this year. Adverts opposing clean air zones were particularly prevalent in Greater Manchester, with 51 placed by local candidates in the period analysed. Trafford Conservatives ran 14 ads criticising clean air zones. One advert that ran in April stated: “Labour have done nothing for you other than spend millions on trying to tax you to drive with Greens and Lib Dems.” The start date for a Manchester CAZ, which would be the UK’s largest, has been delayed after disagreements between the Greater Manchester mayor, Andy Burnham, and the government over funding. Misinformation about the Manchester CAZ has been widely shared on Facebook, according to separate analysis using the analytics tool Crowdtangle. The most popular organic post mentioning the scheme claimed that authorities had cut down trees by a motorway junction near Wigan in order to install CAZ signage. The post later received 43,000 interactions on Facebook when it was reposted by a meme page. A spokesperson for Highways England, which manages the land around the Orrell Interchange, said no trees had been removed to install the sign. Trafford Conservatives said in a statement: “On Thursday, voters in Trafford have a choice. They can vote for a Labour council’s 493 square mile charging zone, supported by the Liberal Democrats and Greens, who all want to make it more expensive and more difficult to get to work, to see your family or to get around your day. “Alternatively, they can vote for a fresh start with the Conservatives, who will prioritise making life easier for hard working families and small businesses.” In London, which has the highest coverage of low-traffic neighbourhoods in the UK, Conservative candidates placed 65 ads pledging to remove them. The highest number were run by local parties in the outer suburban boroughs of Croydon and Enfield. Enfield Conservatives said the Labour administration had not listened to people about two new LTNs and created “more pollution, more congestion”. Official monitoring data from Enfield council shows traffic volumes inside its Fox Lane LTN fell by 72% on average after its introduction, while boundary roads saw an average increase of 6%. Stephen Edwards, the chief executive of Living Streets, said: “Nobody wants to vote for dangerous roads, air pollution and rat running. The government’s own evidence shows that there is overwhelming support for traffic reduction and space being reallocated to people walking, wheeling and cycling.” “Of course, if low-traffic schemes aren’t working, authorities should be working with residents to find other ways to reduce car dominance and prioritise people.”