The Federal Government says Queensland is wasting money by intervening in a legal challenge against the mining tax.

The new Liberal National Party (LNP) Government says the tax discriminates between the states and restricts a its ability to encourage mining.

But Federal Treasurer Wayne Swan says he cannot understand how the LNP Government can spend money on the case when it is sacking public servants to cut costs.

He says the challenge, led by Fortescue Metals Group (FMG), is futile and will not succeed.

"Even the Premier of Western Australia would not entertain a challenge because he knew it would be unsuccessful," he said.

"We are very confident in our legal advice - what you've seen here is political action of the Queensland Government."

"Anyone familiar with the workings of the High Court knows you spend a lot of money when you intervene in a High Court case."

But Queensland Attorney-General Jarrod Bleijie says the intervention will only cost about $300,000.

He says the decision to intervene is about investment in the state.

"We are one of the biggest resources states in Australia along with Western Australia, so it's important we protect that and do everything we can to protect that as much as we can," Mr Bleijie said.

"The more the Federal Government intervene in the way they do business, the less people they're going to employ - and that does impact Queensland."

Federal Opposition Leader Tony Abbott says he sanctions states using taxpayer money to address the issue.

"There is no doubt that the mining tax is bad and targets the resource states," he said.

"If those states wish to challenge the tax in court, that's a perfectly reasonable thing for them to do."

Difficult case

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 3 minutes 29 seconds 3 m 29 s Queensland to join mining tax challenge Download 1.6 MB

Constitutional experts have suggested it will be a difficult case to win, but Mr Bleijie says it will be worth it.

"We certainly don't want to be a government that sits back and regrets this in six months' time as not having a go," he said.

The legal challenge threatens the Federal Government's plan to deliver a budget surplus next year.

The tax came into effect this month and is expected to raise $13 billion over the next four years.

Mr Swan suggested the LNP should be funding the intervention instead of Queensland taxpayers.

The Treasurer claims the aim of the challenge is to support the mining interests of LNP benefactor and preselection candidate Clive Palmer.

But Mr Bleijie dismissed claims and says he has not spoken to Mr Palmer about the legal action.

"No of course not," he said.

The ABC has requested a comment from Mr Palmer.