Rupert Murdoch says business has a right to speak out on public policy matters, even on issues not directly related to their area of operation.
"Business is just as entitled to express its opinion as unions are," the News Corporation executive chairman told the B20 summit of business leaders in Sydney.
"The trouble, I find, is usually unions represent hundreds of thousands of voters whereas a business represents just one."
Mr Murdoch said business had a role to play in shaping public policy in a democracy.
"If we feel we have a contribution to make to the debate we should do so. Certainly my newspapers do so every day and we far from regularly win the argument.
"It's very important that, if we live in a democracy, with real entrepreneurship, you've got to have a world of ideas to debate."
Mr Murdoch said businesses should be involved in shaping public policy and also suggested governments needed to loosen constraints on business.
"You should be leaving the public, by the normal processes of demand, to provide business with the opportunities to get on with life and get the governments to take a back seat," he said.
The B20 is a meeting of 400 business leaders from the world's leading economies, gathered in Sydney to provide a list of recommendations to the G20 group of government leaders.
Mr Murdoch, who was part of a panel discussion on the role of business in shaping public policy, said he held a lifelong belief in free markets and strong libertarian ideals.
"For businesses large and small there's simply too much red tape and too many self-serving politicians stifling economic growth and entrepreneurialism," he said.
Mr Murdoch also defended companies which have been criticised by the US government for relocating to lower corporate-taxing countries.
US Treasury Secretary Jacob Lew called for an end to the practice of "inversion" where companies move their headquarters to lower-taxing countries such as Ireland, naming it a matter of "economic patriotism".
Relatively high corporate tax rates are also an issue for Australia in competing to attract businesses against lower-taxing neighbours such as Singapore.
Mr Murdoch said criticising companies was avoiding a serious debate about tax reform.
"Do we really expect companies to voluntarily bring overseas profits back to be taxed at 35 to 40 per cent in the United States when the corporate tax rate in Ireland is 12.5 per cent?," he said.
"This is not the way to achieve economic growth."
