MRRT will be recalled as worst: Hockey

Federal Treasurer Joe Hockey said Labor's mining tax will be remembered in 100 years time as the worst tax that was ever designed.

The coalition's plan to repeal the minerals resource rent tax (MRRT) was blocked by Labor and the Australian Greens in the Senate on Tuesday.

Mr Hockey told parliament shortly after that the MRRT was originally meant to raise $12.5 billion dollar next year but is hardly raising anything.

The problem is Labor pre-spent $16 billion against a tax that "barely raises a dollar", he said.

"That is irresponsible budgeting," he said in response to a question.

He labelled the MRRT an "abject failure".

"In a 100 years time when tax classes are taught at university they'll go back and say `Mr professor, what was the worst tax that was ever designed'," Mr Hockey said.

"And the professor will respond, `it was the five versions of the mining tax'."

He said the carbon tax is close, but there was only one version of that.