MailOnline is suing Google after alleging the search engine hides links to its articles on topics such as “Meghan Markle” and “Piers Morgan”, setting up a legal battle between one of the world’s biggest news websites and the tech giant.

Google is accused by MailOnline of having too much control over the online advertising market and of systematically downgrading links to its stories in favour of other sites, citing coverage of the royal family.

British users searching for Piers Morgan’s comments on the Duchess of Sussex last month were substantially more likely to see articles about him produced by smaller regional outlets such as the Manchester Evening News and Newcastle Chronicle, MailOnline claimed.

This is despite MailOnline often writing multiple stories a day about the former Good Morning Britain host, who said he “didn’t believe a word” Meghan said in her interview with Oprah Winfrey, and employing him as a columnist.

In the lawsuit, filed in New York and described as “worthless” by Google, MailOnline alleges it is being punished by Google News’s algorithm after attempting to reduce its reliance on Google’s separate tools for selling online advertising.

“This lawsuit is to hold Google to account for their continued anti-competitive behaviour including manipulation of ad auctions and news search results, bid rigging, algorithm bias and exploiting its market power to harm their advertising rivals,” said a spokesperson.

“Despite increased criticism by regulators and governments around the world, Google’s ongoing behaviour clearly shows they are not prepared to change their conduct.” Google said MailOnline’s claims are “meritless”.

MailOnline has become one of the biggest news websites in the world – with a massive US audience – aided by its mix of celebrity pictures, rapid news aggregation and culture war stories.

News websites have an uncomfortable love-and-hate attitude to Google. The search engine can send millions of readers to an outlet if a story is shown prominently alongside popular search terms, allowing the publisher to reach new audiences and sell more advertising. But Google’s dominance of online display advertising means the tech company has become hugely profitable at a time when traditional news publishers have lost ad revenue.

MailOnline’s lawsuit also shows the importance of search engine optimisation (SEO) to news websites. For many years, outlets have commissioned articles featuring certain popular names or keywords in the hope of catching the attention of Google News’ algorithm.

One major issue for all outlets is the lack of transparency on how Google decides which stories to show. Some publishers believe Google favours results from news outlets that produce more original reporting. It increasingly prioritises results from websites which have limited amounts of advertising and are fast-loading, a move which has hit some ad-heavy websites.

Google said it would be fighting the lawsuit. “The Daily Mail’s claims are completely inaccurate. The use of our ad tech tools has no bearing on how a publisher’s website ranks in Google search. More generally, we compete in a crowded and competitive ad tech space where publishers have and exercise multiple options,” a spokesperson said. “The Daily Mail itself authorises dozens of ad tech companies to sell and manage their ad space, including Amazon, Verizon and more. We will defend ourselves against these meritless claims.”