In a statement issued on Monday, Marketers for an Open Web said if Google was allowed to released its so-called Privacy Sandbox technology, that would frustrate efforts by regulators around the globe to ensure that there was fair competition on the Internet.
The sandbox would remove login, advertising and other features from the open Web and place them under Google's control, MOW alleged.
In the event that MOW succeeds, it would mark the first time that the CMA has used its powers to challenge online platforms' growing control of the Internet.
MOW said: "Google’s dominant Chrome browser and Chromium developer tools (which together run on about 72% of UK computers) are currently being modified to give Google even greater control over how publishers, advertisers and other digital businesses can operate on the web. These changes, known as ‘Privacy Sandbox’ are scheduled for full implementation in early 2021.
"Critics say that, despite its name, Google’s new technology has nothing to do with privacy, and everything to do with moving the whole digital advertising industry off the open web, where it supports numerous innovative technology businesses and allows publishers and advertisers to optimise revenue by dealing with the most efficient partners – and into the walled garden of its Chrome browser, where it would be beyond the reach of regulators.
"The changes will deny news publishers access to the cookies they use to sell advertising, thereby cutting their revenues by an estimated two-thirds, with smaller regional titles hardest hit, journalist’s jobs lost, and reliable, fact-checked online news under greater threat than ever."
MOW director James Rosewell said: “The world’s regulators have realised that Google is attempting to take over the Web through its dominance of areas such as search, online advertising and browser technologies.
"However, their efforts to mitigate this monopoly power will be in vain if Google manages to consolidate its dominance through the introduction of Privacy Sandbox prior to the regulators’ recommended changes to the law being implemented.
"If Google releases this technology they will effectively own the means by which media companies, advertisers and technology businesses reach their consumers and that change will be irreversible."
Rosewell said the concept of the open web was based on a decentralised, standards-based environment that was not under the control of any single commercial organisation.
"This model is vital to the health of a free and independent media, to a competitive digital business environment and to the freedom and choice of all Web users," he said. "Privacy Sandbox creates new, Google-owned standards and is an irreversible step towards a Google-owned ‘walled garden’ Web where they control how businesses and users interact online."
iTWire has contacted Google for comment.