More than 500,000 Australians have signed a petition calling for an inquiry into the dominance of Rupert Murdoch’s media empire. The petition to parliament was launched by former Australian Prime Minister Kevin Rudd a little over three weeks ago and closed on Wednesday. It calls for a Royal Commission — Australia’s highest form of public inquiry — to “investigate threats to media diversity.” It also accused media businesses of encouraging “deliberately polarizing and politically manipulated news.” While the petition raised several points of concern, including Google\n \n (GOOGL) and Facebook’s\n \n (FB) relationship with the news media, it singled out Murdoch’s News Corp\n \n (NWS) as a potential threat to free speech and public debate. “We are especially concerned that Australia’s print media is overwhelmingly controlled by News Corporation, founded by Fox News billionaire Rupert Murdoch, with around two-thirds of daily newspaper readership,” the petition said. “This power is routinely used to attack opponents in business and politics by blending editorial opinion with news reporting.” News Corp Australia did not immediately respond to a request for comment. The publisher is one of the largest in the country and owns major national newspaper The Australian and tabloids such as The Daily Telegraph and The Herald Sun. Rudd used social media to tout the response to the petition. “Half-a-million Australians have spoken. They’ve smashed the records to make their voice heard: Australia needs a #MurdochRoyalCommission to protect the lifeblood of our democracy,” he said in a tweet. The petition will likely be presented to Australia’s House of Representatives, but lawmakers are not obligated to act on it. Rudd has been outspoken about what he considers the toxic influence of Murdoch’s media properties. He has called the billionaire’s news empire a “cancer on democracy” in the United States, United Kingdom and Australia, and likened the organization to the mafia in an interview with CNN chief media correspondent Brian Stelter in May. “To call the Murdoch media empire a journalistic organization committed to bringing you fair and balanced news coverage around the world these days has become a joke,” Rudd said. Murdoch’s media empire spans the globe, and its role has also faced scrutiny in the United Kingdom, where News Corp owns newspapers including The Sun and The Times. In 2017, UK regulators spent months investigating 21st Century Fox’s proposed $15 billion takeover of the broadcaster Sky and how it would impact the media market. The government also probed whether Fox would uphold UK broadcasting standards. That deal never materialized. Fox eventually lost the battle for Sky to Comcast\n \n (CCZ), while Disney\n \n (DIS) spent tens of billions of dollars to pick up most of Fox’s assets — excluding Fox News Channel, Fox Sports and the Fox broadcast network. Like many other news organizations, News Corp Australia is also dealing with disruptions to its business caused by the Covid-19 pandemic. The company announced earlier this year that it would be shutting down dozens of local newspapers in Australia and ending print production for most of its smaller publications as part of a major shakeup of its business in the country. The global media industry has been slammed as the coronavirus pandemic reduces demand for advertising. — Michelle Toh contributed to this report.