Gina Rinehart, Australia's richest person, refuses to be muzzled even if her controversial comments generate debate in the country. After her hit column in a mining industry magazine which came out last week, Ms Rinehart used on Wednesday popular video sharing site YouTube to air her thoughts once more on national issues.

Also the world's richest woman, Ms Rinehart said that Australia is too expensive and uncompetitive for exporters mainly due to the carbon tax and minerals resource rent tax which she has consistently opposed.

"Now the evidence is unarguable - that Australia is indeed becoming too expensive and too uncompetitive to do export-orientated business," she said at the video posted on the Sydney Mining Club Web site.

"Our federal and state governments must know that now, more than ever, we must lift our international competitiveness just to stay as well off as we are. And with state and federal debts we must get realistic - not just promote class warfare," she added.

"What was too readily argued as the self-interest complaints of a greedy few is now becoming the accepted truth, and more ominously, is showing up in incontrovertible data," Ms Rinehart pointed out.

The mining tycoon's previous suggestions for a cut in the weekly minimum wage rate of $606.40 per week and for Australians to smoke and drink less and work more generated criticisms across Australia. Critics pointed out that she became rich not so much for hard work but because she inherited wealth from her father.

Treasurer Wayne Swan, who was one of those who reacted to Ms Rinehart's magazine column, again spoke against the billionaire's latest rant delivered at the Association of Mining and Exploration Companies conference in Perth.

"The only Australian not getting sick and tired of this almost-daily pearl-rattling from Gina Rinehart is her loyal servant Tony Abbott. Not only has Gina Rinehart told her paymaster Tony Abbott he should consider slashing the minimum wage, now she says a competitive way to lower labour costs is by utilising illegal labour," The Australian Financial Review quoted the treasurer's spokesman.

West Australian Mines Minister Norman Moore and Fortescue Metals Group Chairman Andrew Forrest, who are against the mining tax, backed Ms Rinehart's latest statement. Mr Moore said the billionaire should be credited, not criticised for her investment in mining projects.

A letter writer to Courier Mail also wrote that there are some grains on truth in Ms Rinehart's column. While Dr Paul Williams, senior lecturer at Griffith University's School of Humanities, disagreed with her suggestion to cut the minimum wage, he sided with her other suggestion for Aussies to drink and smoke less but work harder.

He pointed out that the average alcohol consumption of 10 litres per Australian makes Aussies among the world's top guzzlers in the same ranking as Russian drinkers and ahead of Americans, Japanese and Swedish drinkers.

With recent changes in work-life balance, full-time employees worked just a little more than 39 hours a week and increased their weekly leisure time to 78 hours or a boost by 46 per cent.

"For far too long, Australians fearful of the tall poppy have reveled in an inverse snobbery. It's therefore right that Rinehart should also call for an end to the phoney class war," Mr Williams wrote.