Over 90% of vehicles operated by local authorities run on diesel despite council efforts to tackle air pollution, new research has revealed.

A car news website has found that an average of 91.6% of council vehicles use diesel and 62 council fleets consist entirely of diesel vehicles.

It has also discovered that London authorities are still running 724 non-ULEZ-compliant diesel vehicles.

The website Auto Express’s findings are based on responses to a freedom of information request from 320 councils in England, Scotland, Wales and Northern Ireland. Between them these councils operate 66,617 vehicles.

Bristol City Council was recently forced to suspend its roll-out of a new vehicle fleet after purchasing dozens of diesel vehicles despite planning to introduce a city centre diesel ban.

Of the 135 new vehicles already introduced for use across all the council’s services, 64 were diesel. The council said they were ‘purchased due to suitable petrol equivalents being unavailable’.

Responding to Auto Express’ research, a spokesperson for the Local Government Association said: ‘Councils are eager to switch to electric vehicles or low emission alternatives where possible and some are already reviewing their fleets.

‘However, the vast majority of the types of specialist vehicles councils operate do not have viable electric alternatives because they simply don’t exist.

‘This is expected to change in the future once new electric models enter the market.

‘Specialised vehicles may well be the last to electrify as they form such a small part of the overall vehicle fleet, that manufacturers will most likely electrify larger volume ranges first.’