Subaru has removed all of its diesel-engined models from sale in the UK, in a move likely to be caused by the incoming WLTP emissions test regulations.

The Japanese brand's latest models, the Impreza hatchback and XV SUV, were introduced without the option of a diesel engine. Now, all references to the 2.0-litre boxer diesel unit previously offered in the Forester and Outback have been removed from Subaru's website. 

The move comes as a surprise because the oil-burning variants of Subaru's largest models were the volume sellers in the range. Buyers of the Forester can now only choose a 2.0-litre boxer petrol engine, with or without a turbocharger. The Outback's sole engine choice is a naturally aspirated 2.5-litre petrol mated to a CVT gearbox.

Subaru's decision to drop its 2.0-litre diesel engine is almost certainly due to it not meeting the standards of the WLTP (Worldwide Harmonised Light Vehicles Test Procedure) regulations, which come into force next month.

Many manufacturers are being forced to re-engineer powertrains to ensure published CO2 and fuel economy figures don't increase dramatically under the new regime.

Dealer stock of diesel Subarus is still available to buy, but no pre-WLTP cars can be registered by manufacturers from 1 September.