Most Australians would probably not choose to spend their weekends browsing Parliament’s website.
But a petition calling for a public inquiry into Rupert Murdoch’s media empire in Australia, posted by a former prime minister, generated so much interest over the weekend that it overwhelmed the website’s cyberdefenses and shut down access to the document.
The petition — posted on Friday by former Prime Minister Kevin Rudd — asks the government to establish a Royal Commission, the country’s highest form of inquiry, into the dominance of Australian media by Mr. Murdoch’s News Corp and its impact on the country’s political landscape.
“Murdoch has become a cancer — an arrogant cancer on our democracy,” Mr. Rudd said in a Twitter video on Friday. An inquiry, he added, would “maximize media diversity ownership for the future lifeblood of our democratic system.”
The move was a very public attempt to challenge Mr. Murdoch, 89, and his global media empire, which contributed to the rise of right-wing politics and helped reshape democratic governments around the world.
In the United States, Mr. Murdoch’s Fox News Channel and New York Post have been leading supporters of President Trump and critics of President Obama and other Democrats. His British newspapers are conservative stalwarts and one of them, the tabloid The Sun, was a leading booster of the successful campaign for Britain to leave the European Union.
But nowhere is his influence greater than in Australia, where News Corp controls about two-thirds of daily newspaper circulation, and Mr. Murdoch also controls prominent news channels like Sky News Australia.
Ousted prime ministers like Mr. Rudd, of the center-left Australian Labor Party, have said News Corp and its outsized presence were partly to blame for their falls. And, critics say, News Corp outlets have undermined efforts to fight climate change, pushed governments into hard-line policies on issues like migration, and employed language and images widely seen as racist.
The company did not immediately respond to a request for comment. Mr. Murdoch has said that he is a climate-change skeptic, and his outlets have repeatedly denied charges of racism.
A center-right former prime minister, Malcolm Turnbull, has also been very vocal about his clashes with Mr. Murdoch, who he says helped drive him from power, in favor of a politician farther to the right.
By Monday night, over 200,000 people had signed Mr. Rudd’s petition — even as technical issues over the weekend prevented some users from accessing the site.
Such was the volume of traffic that it triggered defenses designed to stop bots from manipulating the site, the Australian House of Representatives said, adding that the website saw a 500 percent spike in traffic over the weekend.
The site has since increased its capacity, it said, and the petition will close on Nov. 4.
Even if support for the petition rises, the government, a coalition of conservative parties, is unlikely to approve a Royal Commission, and would not want to antagonize Mr. Murdoch, media and political analysts say.
Even Anthony Albanese, the head of the opposition Labor party, has distanced himself from the petition filed by Mr. Rudd, who has long called for an investigation into News Corp’s influence in Australia. Mr. Rudd served as Australia’s prime minister from 2007 to 2010, and for a few months in 2013, and is currently the president of the Asia Society Policy Institute.
But the petition has tapped into a “a deep reservoir of discontent and frustration,” said Timothy Dwyer, an associate professor of media and communications at the University of Sydney, particularly among younger, center-left voters who oppose the climate change skepticism that has been a feature of Mr. Murdoch’s media outlets.
David McKnight, an associate professor of media at the University of New South Wales, said Mr. Murdoch’s role in Australia highlighted the need for more public interest journalism.
“Mr. Murdoch has a long history of interfering or trying to swing the result in elections,” he said. The blurring of opinion and news, and the shift in media consumption to online and social media, have given more even weight to News Corp, he added.
Critics have pointed to a New York Times interview, published on Saturday, with one of Mr. Murdoch’s adult children, James Murdoch, who was once seen as a potential successor to run his father’s business. James Murdoch said that he had resigned from the News Corp board because of growing discomfort over the agenda of Fox News and other outlets.
“A contest of ideas shouldn’t be used to legitimize disinformation,” he said.
Even without immediate action from the government, analysts say anger against the elder Mr. Murdoch will continue to simmer.
The question is whether a movement to build more media diversity — and in turn, address Mr. Murdoch’s dominance — will gain more momentum in the future, said Mr. McKnight. “People have long memories,” he said.