On the other hand, government has not taken the responsibility it should for national messaging on the need for air quality measures. We asked Defra and DfT why Government had decided against a national communication campaign about the new charging Clean Air Zones (CAZs) that are coming into effect through the NO2 programme in favour of a locally-led approach. They told us that this was because they consider local places are best placed to judge how to communicate with their residents, and because they consider that local awareness of which vehicles are subject to a charge is the priority.34 However, surveys in the first two cities with CAZs, Bath and Birmingham, showed that the local campaigns had mixed results. They did not result in a statistically significant increase in the percentage of residents who ‘know a great deal’ or ‘fair amount’ about the CAZ, and the reasons for the CAZ were misunderstood by a substantial minority of those surveyed in both cities, with many believing the purpose was to raise revenue for the local authority.35 27 Follow-up response submitted by Defra and DfT dated 11 July 2022 28 C&AG’s Report, para 2.12 29 Q 34, 40 30 Q 35 31 C&AG’s Report, para 2.21 32 Q 35 33 Q 41 34 Qq 50, 51 35 C&AG’s Report, para 3.28 12 Tackling local air quality breaches Moreover, the experience of Covid-19 showed that the success of local communications partly depends on a strong national message about what is to be achieved; if the national message does not come through, local authorities will struggle.36 Public spending on air quality