£1500 off Renault, Nissan, Citroën, Vauxhall EVs as grant list grows

He also noted that the Japanese firm has three new EVs on the way, referring to the Sunderland-built electric Juke, Qashqai and Leaf - the last of which is due imminently and is in a "very strong position" to benefit from the maximum £3750 grant.

Meanwhile, the UK-built Citroën e-Berlingo and Vauxhall Combo Life Electric have been awarded the lower discount. This is likely to be because their batteries come from abroad, while the Nissan Leaf's battery will be supplied by the AESC factory next to Nissan's Sunderland plant. 

The government has not given any indication of when to expect the next batch of ECG-eligible EVs, but many sub-£37k EVs – including many from Asia that are unlikely to be deemed eligible on the basis of their manufacturing and export CO2 footprints – have already been discounted by their makers.

Unlike with the previous Plug-in Car Grant (PiCG), buyers don't need to register for the discount; instead, the ECG is automatically applied to the sale price of the eligible models.

Transport secretary Heidi Alexander said: “This summer, we’re making owning an electric car cheaper, easier and a reality for thousands more people across the UK.”

To qualify for the grant, car manufacturers' models must meet science-backed emission-footprint criteria, while the individual model lines must be priced under £37,000 in entry-level trim.

Which discount a model receives – either £1500 or £3750 – is determined by its environmental impact: how much CO2 is emitted in an EV's production and assembly, along with the emissions footprint of its battery manufacture. Threshold levels have yet to be made public.

While any manufacturer can apply for their car to be included in the scheme, it's thought that, due to this criteria, cars produced in Asian countries will not be eligible for the ECG.

Worries about manipulation of the scheme have already been raised. For instance, sources have revealed to Autocar that car makers will be able to self-register EVs to receive the ECG.