in London as "gold bricks for investment", instead urging them to invest in the construction of "affordable homes" for Londoners through a new agency, Homes for Londoners, which would be funded by both public and private money. Homes for Londoners is governed by a board and chaired by Khan. However, in contrast to one of his pre-election statements, he revealed that he no longer supported rent freezes in the city. By 2022, Khan had reverted to supporting rent freezes. Khan vetoed the construction of a football stadium and two blocks of flats on Green Belt land in Chislehurst, after the plan had already been supported by Bromley Council, insisting that he would "oppose building on the Green Belt, which is now even more important than when it was created". Khan launched a "No Nights Sleeping Rough" taskforce to tackle youth homelessness in London in October 2016. Air pollution Khan has called air pollution “the biggest public health emergency of a generation.” In October 2017, he introduced the Toxicity Charge (T-charge); operating within the same hours and zone as the London congestion charge, the T-Charge levied a £10 fine on top of that for older and more polluting vehicles (typically diesel and petrol ones registered before 2006) that do not meet Euro 4 standards. In that same year, he announced plans to establish a replacement: an "Ultra Low Emission Zone (ULEZ)" that would charge owners of the most polluting cars a fine of £12.50 per day on top of the congestion charge. The all day, every day (except on Christmas Day) zone was introduced in 2019 in Central London, extended to the North and South Circulars in 2021, and will be extended to the whole of Greater London from 2023. The charge applies to diesel cars and vans whose engines aren't at the latest Euro 6 standard as well as most petrol cars pre-2005; in addition, non-compliant buses, coaches and lorries must pay £100. The initial zone resulted in a drop of the worst polluting vehicles entering the zone each day from 35,578 in March 2019 to 26,195 in April after the charge was introduced. Khan criticised the UK government in June 2017 for its lack of drive in improving general air quality. He stated that the government's action plan on the issue lacked “serious detail, fails to tackle all emission sources, such as from buildings, construction or the river, and