The Media Rating Council has suspended Nielsen’s accreditation for national ratings, the latest twist in a long-running drama over the effort for a third party to effectively measure viewing.

The move, which will take effect in mid-September, applies to Nielsen’s national television service as well as Local People Meters and Set Meter Markets. Such suspensions occur, the MRC explained, when a company is found to have “material standards non-compliance or operational issues that are deemed to have exerted an adverse effect on the service.”

Opinions vary as to the importance of the MRC’s decision. Nielsen will continue to be free to deliver its data to its customers and report it publicly, though the episode could give more ammunition to critics who insist it has been undercounting viewing.

The MRC is a non-profit organization set up in 1963 to monitor stakeholders in the television business in the wake of the quiz-show scandals of the 1950s. A fairly obscure body, it audits more than 100 ratings products across television, radio, print and digital media, as well as in the advertising and measurement sectors. Its CEO, George Ivie, said the “broad range of industry constituencies” is “strongly unified in its positions on these matters.”

A Nielsen spokesperson responded to the MRC’s move by saying it would not slow the company’s data flow. “While we are disappointed with this outcome, the suspension will not impact the usability of our data,” the spokesperson said. “Nielsen remains the currency of choice for media companies, advertisers and agencies. We are committed to the audit process and during this pause in accreditation we will work with the MRC on resolving this suspension. We will also take the opportunity to focus on innovating our core products and continue to deliver data that clients can rely on, ultimately creating a better media future for the entire industry.”

In recent months, media companies and advertisers have ramped up criticism of Nielsen. NBCUniversal recently issued a request for proposals to a wide array of third-party firms, seeking to create a new system of measurement. As long as the Nielsen Co. has existed, its methods have been criticized by those invested in the TV bundle, which remains worth about $70 billion in annual advertising. Streaming has created massive disruption to the way viewing is counted, with tech players exerting enormous control over the data harvested from their customers.

At issue with the MRC and the VAB specifically was Nielsen’s decision to pull field employees back during Covid-19. They say that resulted in undercounting of both linear and streaming viewership. Nielsen has said that it made the call out of safety concerns for workers.