Question to the Department for Transport:

To ask the Secretary of State for Transport, how many and what proportion of buses are (a) zero-emission and (b) non-zero-emission.

Statistics on the number and proportion of zero‑emission and non‑zero‑emission buses are published in the Department for Transport’s Annual bus statistics, table BUS06e (Vehicles operated by local bus operators). The tables are available at:
https://www.gov.uk/government/statistical-data-sets/bus-statistics-data-tables.