Demand for new alternatively-fuelled cars has fallen for the first time in more than two years, new figures show.
Some 13,314 of the cars were registered in the UK last month, down 11.8% on the 15,099 registered during June 2018.
The Society of Motor Manufacturers and Traders (SMMT), which published the data, said the decline was driven by a reduction in sales of hybrid cars.
It is the first time the alternatively fuelled car sector has seen negative growth since April 2017.
Government grants for new low-emission cars were slashed in October last year, meaning hybrid models are no longer eligible for the scheme.
The Government announced a plan last summer to ban the sale of new petrol and diesel cars and vans by 2040.
Meanwhile, the overall new car market declined for a fourth consecutive month in June, with demand falling by 4.9% year-on-year.
Diesel models were down 20.5%, while petrol saw a 3.0% rise.
SMMT chief executive Mike Hawes said: “Another month of decline is worrying but the fact that sales of alternatively-fuelled cars are going into reverse is a grave concern.
“Manufacturers have invested billions to bring these vehicles to market but their efforts are now being undermined by confusing policies and the premature removal of purchase incentives.
“If we are to see widespread uptake of these vehicles, which are an essential part of a smooth transition to zero-emission transport, we need world-class, long-term incentives and substantial investment in infrastructure.
“Fleet renewal remains the quickest way to address environmental concerns today and consumers should have the confidence and support to choose the new car that best meets their driving needs, whatever the technology, secure in the knowledge that it is safer and cleaner than ever before.”