Motorists risk overpaying for EV costs as major error causes chaos ahead of Rachel Reeves' new taxes

The findings have been submitted to Parliament's Transport Select Committee, raising concerns that some EV drivers could be paying more than they should.

Around 15 per cent of the chargers tested by EVCI Global showed errors of more than five per cent, while a small number were said to have "materially larger deviations" from the correct figures.

In one extreme case, the company said a charger delivered 37 per cent less electricity than it claimed on its display.

Craig Marsden, chief executive of EVCI Global, said: "People with EVs need to know that they're getting what they're paying for, the same way that they do at petrol pumps."

The issue follows growing concerns around charging costs, with drivers already struggling with an expensive public network, with prices as high as 89p per kilowatt hour.

Drivers who rely entirely on public charging points can face yearly bills close to £2,000, with experts warning that this could climb further if chargers overestimate the electricity delivered.

Chancellor Rachel Reeves has announced a pay-per-mile levy for electric vehicles from 2028, meaning EV owners will pay 3p per mile, while hybrid vehicles will be charged 1.5p per mile from 2028 on top of fuel duty.

Petrol pumps are tightly regulated and must be accurate within a tolerance of just 0.5 to one per cent, with regular inspections.

EVCI Global warned this creates "a two-tier system of consumer protection where EV drivers are currently exposed to significantly higher financial risk than drivers of combustion engine vehicles".

The firm has now urged the Government to introduce a formal verification system for EV chargers, similar to the rules that apply to petrol forecourts.

Mr Marsden confirmed his company has held discussions with Government departments about bringing in mandatory checks.

However, in some cases, chargers were found to underestimate the electricity delivered, meaning drivers were billed less than they should have been.

The charging industry has pushed back against the claims, with trade body ChargeUK stating the problems appear limited rather than widespread.

Jarrod Birch, head of policy at ChargeUK, told The Telegraph: "Charge point operators, auto manufacturers and drivers all care about accuracy but currently the evidence suggests isolated issues rather than a widespread problem."

The Department for Transport said public chargers are expected to deliver the amount of electricity shown on the screen.

A spokesperson added that meters at most public charge points are already covered by rules requiring accuracy within two per cent.