The Advertising Standards Authority (ASA) upheld a challenge by nine complainants that Anglian Water ads were misleading because they omitted the company's history of releasing sewage.

The TV and video on demand ad - which appeared in September and October last year - cannot be aired in its current format again and the ASA has said future adverts must be "adequately qualified" when making environmental claims and must not omit "material information" about the negative impact the company had on the environment.

In the ad, the water provider for the east of England, said it was creating wetlands to clear water using nature. It also said it was protecting nature, using tanks to collect rain to prevent flooding. "In fact, everything they do today is for tomorrow", a voiceover said.

Read more
Good news on fall in sewage spills only highlights the scale of the challenge facing water companies
Why addressing sewage spills was not a priority for the water industry or for Ofwat

In reaching its decision, the ASA considered the fact Anglian Water had fallen below expected standards in a number of environmental performance assessments (EPA).

Latest EPA reports, from 2021, showed Anglian Water performed "below target" for the number of sewerage pollution incidents and for compliance with their discharge permit.

Performance was also "significantly below target" for the number of serious pollution incidents. Enforcement action was also taken against the company over recent years for environmental permitting regulations offences.

It was accepted by the ASA that Anglian Water carries out activities that could have a positive impact on the environment, but it also carried out harmful activities, which contradicted the impression created in the ad.

As a result, the omission of the harmful activities was deemed to be misleading, and a breach of advertising codes.

Click to subscribe to the Sky News Daily wherever you get your podcasts

Codes say the basis of environmental claims must be clear, and that unqualified claims could mislead if they omit significant information.

But Anglian Water denies this. It said it had an overwhelmingly positive impact on the environment when all activities are taken into account and it did not believe that any significant information had been omitted from the advertising campaign.

The company no longer builds storm overflows and it works to remove them and reduce the frequency of their use, it said. Anglian Water said it was true to say that all the work they were actively engaged in was to secure a more prosperous future for the region.

Water companies across the UK have come under pressure after the Environment Agency said a total of 301,091 spills were recorded last year - 824 a day on average. Water companies were urged by the agency to improve the maintenance, management and investment of their systems.

Firms across the UK apologised for "not acting quickly enough" and said they'd spend £10bn to prevent spills.