Entrepreneur Dick Smith has launched a stinging attack on News Corp and Kim Williams, the head of its local operations, News Ltd, branding the organisation's campaign against proposed media reforms as hypocritical.

Mr Smith said News Ltd's claim that proposed media regulations would curtail freedom of speech was ''claptrap'' because Mr Murdoch's papers and organisation regularly censored any criticism of it. Mr Smith went on to attack its unwillingness to tackle issues such as anthropogenic climate change.

In the past month, Mr Williams has launched a campaign to prevent any further regulation of the media, stating he was prepared to go to the High Court to stop the introduction of more laws.

In the letter, Mr Smith, who is a vocal supporter of the need to act on climate change, said that it was in News's commercial interests to oppose the idea that people were responsible for the rise in global temperatures.

''And I'm on to you. When friends ask me why your organisation runs such opposing views on climate change - from Fox News's claims that it's all bunkum to The Australian newspaper occasionally claiming it's accepted science - I am able to say: 'It's simple,''' he writes.

''They have worked out they will get more advertising and make more money on Fox News if climate change is debunked using sensationalism while they are likely to get greater circulation and more advertising dollars if The Australian shows a different view, so staff are directed accordingly.''

In April Mr Smith said that he tried to book an ad in Sydney's Daily Telegraph that offered a $5000 reward to any journalist who could get the issue of climate change covered in one of Mr Williams's newspapers.

''A News Ltd spokesman said: ''Contrary to his accusations of censorship, Dick's views are well known to our readers given we publish his articles and opinions regularly … Dick's original ad … seemed to be encouraging a 'cash for comment' type situation. We agreed to publish a revised version, but Dick declined.''

Dick Smith Attacks News Ltd