The Australian government has promised an inquiry into the country's media as politicians complain that Rupert Murdoch's News Corp owns too many newspapers.

Calls have been growing for an Australian inquiry into News Corp since the New York-based company closed the News of the World in July over phone-hacking allegations. News Corp owns 70% of Australia's newspapers.

The communications minister, Stephen Conroy, told colleagues in his ruling centre-left Labor party on Tuesday that there would be an inquiry into the Australian media. He said the terms of reference were under discussion with the Greens party that supports Labor's minority government.

But Conroy said the inquiry would not be "an attack on News Ltd", the Australian subsidiary of News Corp. He said the inquiry could cover areas including protections for privacy and the role of the print media's self-regulatory watchdog, Australian Press Council.

Conroy said the government disagreed with a motion to be proposed by the Greens leader, Bob Brown, in the Senate on Thursday. That motion would call on Conroy to "investigate the direct or indirect ramifications for Australia of the criminal matters affecting" News Corp's British subsidiary, News International.

There have been no allegations made in Australia of the type of phone hacking that has led to at least 16 arrests in Britain.

Labor politicians have long complained that News Ltd publications are biased towards Liberal party conservatives and that the company has too much control over Australian newspapers.

They blame the media for their party plumbing record lows in opinion polls four years after Labor first came to government.

The Liberal leader, Tony Abbott, dismissed the need for a media inquiry, saying there was no evidence of any new problems in the industry. "This looks like a naked attempt to intimidate the media," Abbott said.

The prime minister, Julia Gillard, has had an increasingly testy relationship with News Ltd publications and its executives. The Australian newspaper withdrew an opinion piece from its website and published an apology last month after Gillard threatened to sue over an incorrect claim that she had once shared a house with a corrupt union official that had been paid for with embezzled union money.

Gillard attacked the News Ltd broadsheet, saying no one had contacted her for comment before publishing "a false report in breach of all known standards of journalism". "This is a question of ethics and standards for the Australian," she said.

John Hartigan, chairman and chief executive of News Ltd, described Gillard's comments as "pedantic" and "disappointing", and said it was accepted practice not to seek comment for opinion pieces.