Elsewhere, experts complain the tax situation for EVs is already hurting sales to private consumers.
Critics have long complained of the “driveway divide”, where those who cannot charge an EV outside their own home must rely on more expensive public chargers. Differing rates of VAT mean the levy on home electricity is just 5pc compared to a 20pc rate on public charging.
When fully charging up an EV, this can amount to a difference of as much as £20. EV and driving groups including the RAC have called for a cut in the public charging VAT rate.
Meanwhile, the SMMT wants the Chancellor to cut the rate of VAT on new electric car sales from 20pc to 10pc.
The lobby group claims this would reduce the average price of an EV by £4,000 and generate an extra 270,000 sales over three years.
It would cost the Treasury around £7.7bn, however – a tricky request for Reeves to fulfil when she is already struggling to balance the nation’s books.
Meanwhile, Munoz, at JATO Dynamics, points out that cash-strapped governments across Europe have more recently tended towards rolling back generous tax breaks and incentives for EVs, including in Germany.
“No industry can depend on incentives for all of its life, because of course that would mean it was not profitable,” Munoz adds.
“Car makers are doing their part by bringing more affordable EVs out but we’re not there yet, and these vehicles still remain very expensive.
“Yet it seems that governments are losing patience.”
Ramping up the cost of owning an EV now could have a negative snowball effect, warns Andrew Bergbaum, a partner and automotive expert at consultancy AlixPartners.
“EV sales don’t really have momentum and our modelling suggests that un-incentivised sales will not reach government targets,” he says.
“Anything which further burdens the cost of buying and running an EV will have negative effects.”
As Reeves battles to plug budget shortfalls, the risk is that the Chancellor taxes EVs into oblivion.