After having served multi-billion dollar Future Fund for six years, David Murray ended his term as Chairman last Monday and has left very stinging words to say about the carbon tax.

According to Murray, the carbon tax is the “worst piece of economic reform” he has ever seen.

"If you want me to tell you my view, it is the worst piece of economic reform I have ever seen in my life in this country. The consequence of introducing that tax at that level in Australia today is very, very bad for this economy, particularly in terms of its international competitiveness. It raises costs further within Australia, it reduces our competitiveness for export of energy-related commodities, and it therefore renders us less competitive in the future,” he said.

Coming July 1, carbon pricing scheme will take effect and it will be charging $23 per tonne of carbon that each of the country’s 500 biggest companies will use. According to Murray in a past interview, there is no connection between carbon dioxide and global warming.

However, Treasure Wayne Swan is quick to respond saying that “carbon price scheme is the world’s best practice.

"Mr Murray is a well-known opponent of the science of climate change. I just reject what Mr Murray has had to say about this fundamental economic reform which goes to the core of our future economic prosperity. Big reforms like this are tough reforms, they're never easy, and you will get vested interests and people like Mr Murray out there opposing them. It's not a surprise to me that Mr Murray might oppose a policy of this government,” he said.

It can be noted that this is not the first time that Murray has criticized the government. He was also vocal about his disagreement to the mining tax.