Smart Energy GB has resolved all but one of its complaints with the Advertising Standards Agency (ASA), its chief executive has revealed.

In correspondence with the Business, Energy and Industrial Strategy select committee, Sacha Deshmukh has written that the advertising watchdog received eight complaints about the smart meter promotion body’s campaign last year.

Of these complaints, he wrote to the committee’s chair Rachel Reeves MP that just one is now unresolved with the remainder having either not been upheld or resolved with no need for formal adjudication.

The unresolved complaint, lodged in July 2018, challenges Smart Energy GB’s claim in radio and press adverts that using one of the devices could deliver an average saving of 354kWh.

The complaint also queries the advert’s claims that “You could save energy to charge your phone for this many years -177”, and “You could save energy to power every home in Aberdeen, Cardiff and Manchester for this many days – 365”.

The complaint says the claims in the advert are “misleading” and “could be substantiated”.

Deshmukh writes that Smart Energy GB is confident that the claims made in the adverts are “not only accurate, but..conservative,” adding that they are based on the assumption that users of smart meters will cut their energy use by 2 per cent, lower than the 2.8 per cent expected electricity saving cited in the government’s official cost benefit analysis for the rollout of the devices.

He also defends the use of the figures in the adverts on the ground that they were cleared by the “relevant advisory bodies” ahead of publication

The organisation is currently waiting for a final verdict from the ASA.

He writes that it is “common” for prominent advertisers to be subject to complaints to the ASA, which he writes sets an “extremely low” bar to trigger an investigation.

The letter was prompted by a question from ex-shadow energy and climate secretary of state Caroline Flint to minister Claire Perry at a hearing earlier this month into the findings of the National Audit Office’s inquiry into the smart meter rollout.

In October last year Smart Energy GB informally resolved a case regarding its advertising of smart meters with the ASA.

Concerns were raised about an advertorial which was “written by and published in” the Daily Telegraph in which it was claimed smart meters will be installed for “free”.

Following an informal intervention by the ASA, the national campaign for the smart meter rollout agreed to reword its advertising.