Clean Air Zones (CAZs) are the UK Government’s key mechanism for reducing NO2 from road transport to legal levels “in the shortest possible time”, but they illustrate the Government’s over-reliance on local government to deliver progress. CAZs were already being held up before the pandemic by delays in national funding, lack of national support and local delays. The Government’s updated CAZ- timetable provides only a partial picture with regards to all the local authorities that had been directed to consider whether to introduce CAZs. Many CAZs have been further held up by the pandemic so a concerted effort is needed to achieve faster progress, requiring a more cooperative and joined-up approach between national and local government, as well as more funding. Although local NO2 levels may fall below legal limits over time because of wider changes, in the interim, many local residents will die or suffer health impacts. We also note that some questions remain about the measurement and accuracy of air quality across the country. The Government should, in its response to this report, set out revised timetables for when all the proposed CAZs in England will be implemented and ensure that they are “the shortest possible time”. It should set out the current position with regards to those local authorities which have decided to introduce alternative measures to CAZs, and for those authorities which may be reviewing their proposals because of the pandemic. It should also review what further resources are needed to ensure those timetables don’t slip further.