OPINION: News Ltd's CEO, Kim Williams, launched a stinging attack last week on proposals to introduce a public interest test for media ownership and to replace print media self-regulation with a new statutory body. He declared them ''preposterous and foolish'' and ''a democratic and totalitarian disease'' because they would bring about greater government control of the media and stifle freedom of speech.

He also promised to challenge such measures in the High Court. Williams's threat is unusual given no legislation has been passed, nor has the government even declared its hand. It shows how opponents of federal government policies are willing to quickly shift their focus from Parliament to the courts.

However, as with the mining tax and carbon price, a constitutional attack on new print media regulation is very unlikely to succeed.

The Commonwealth has always had the capacity to regulate television and radio because of the High Court finding that they fall under the power in section 51 of the constitution to make laws for ''postal, telegraphic, telephonic, and other like services''. On the other hand, there is no suggestion these words extend to the print media.

The limits of Commonwealth power are one reason why Australia has extensive federal laws for television and radio, but not newspapers.

The possibilities for regulating print opened up in 2006 when the High Court upheld John Howard's Work Choices legislation. In doing so, judges gave a very wide reading to the federal power over ''trading corporations''.

Since 2006, the Federal Parliament has been able to pass laws extending to the activities of trading corporations that run newspapers. This gives it a solid constitutional foundation upon which to regulate bodies such as News Ltd and Fairfax by determining whether they should be permitted to own and run newspapers and how they should deal with complaints.

Williams suggested this could be subject to constitutional attack because it breaches free speech principles. But Australia lacks a national bill of rights and the constitution contains no express protection of free speech, let alone anything like the ''freedom of the press'' of the US constitution.

This explains why organisations such as Fairfax, News Ltd and Australia's Right to Know coalition have long argued for stronger protection of freedom of speech in Australia. Unfortunately, this has not been forthcoming. The result is reflected in Australia slipping from 18 to 30 in the most recent international press rankings of Reporters Without Borders.

The best hook for Williams's challenge is the High Court finding that the constitution contains an implied freedom of political communication. The court has used this to reshape Australian defamation law to give stronger protection to speech about politicians and politics. However, the current High Court has shown little enthusiasm for applying it.

A good example is a High Court decision from earlier this year. Queensland law makes it an offence for a journalist to interview a prisoner or a person on parole, unless the journalist has secured written approval from the head of corrective services. This was challenged by Lex Wotton, who was on parole after being jailed for his involvement in the 2004 Palm Island riot.

The High Court rejected his attack. It recognised that the Queensland law burdens freedom of communication about government or political matters. However, in only a few paragraphs, it held that this was appropriate because the law sought to enhance community safety and crime prevention.

The Wotton case is a clear illustration of the weak state of legal protection of freedom of speech and of the press in Australia. The Queensland law also provides a model whereby journalists can be denied the right to interview other people, such as asylum seekers and people suffering mental illness, unless a government official agrees to the request. In any event, the horse may already have bolted when it comes to government regulation of the media. Federal law contains extensive laws for controlling television and radio through licensing conditions, and content and accountability provisions. It has also created regulatory bodies such as the Australian Communications and Media Authority.

If federal regulation is constitutionally valid with respect to radio and television, it is hard to see why newspapers are in a different position. There is no reason why the print media has a higher claim to freedom of speech. All this suggests that a High Court attack on new federal regulation of the print media has little chance of success.

George Williams is a Professor of Law at UNSW

This opinion piece first appeared in The Sydney Morning Herald