In May 2017, Transport for Greater Manchester said that it was considering bringing in a revenue neutral £7.50 daily charge for drivers of polluting vehicles as part of plans for Clean Air Zones. However Andy Burnham, Mayor of Greater Manchester, said that he would not introduce such a charge, although legal responsibility lies with councils rather than the Mayor. In September 2018, the leaders of the local councils in Greater Manchester met to discuss charging the most polluting vehicles in a bid to improve the poor air quality in Manchester, which is responsible for around 1,000 premature deaths a year. Around 20% of private cars in the region, mostly pre-2015 diesels, and 70% of buses would be hit by the charge. The council leaders have a statutory responsibility to present plans reducing the amount of harmful nitrogen oxide in the air to legal limits to the Department of Environment, Food and Rural Affairs by December 31 2018 and must implement a Clean Air Zone unless a suitable alternative compliance strategy can be identified. To meet the statutory requirements other cities such as Birmingham and Leeds have already decided to introduce Clean Air Zones while London is expanding its existing zones operating hours to 24 hours per day.