Australia's big mining leaders will sit down with Treasury this week to negotiate on the proposed super profits mining tax.

The Federal Government continues its campaign for a 40 per cent tax on above normal profits of the mining industry.

Several mining companies have expressed their disappointment on the government on imposing the tax, stating that it could put the economy at risk and drive investors away.

BHP chief executive Marius Kloppers stated in a local television channel over the weekend that mining tax appeared “opportunistic.”

"This is clearly what I would call a retroactive tax grab," he said.

Mr. Kloppers explained the mining industry helped Australia during the global financial crisis.

"I think this tax is pretty opportunistic to fill a budget gap." he said.

Meanwhile, the West Australian Chamber of Commerce and Industry has signed a petition to Prime Minister Kevin Rudd to revise his decision on the mining tax.

The chamber said a 40 per cent tax on miners will be “damaging.”

However, the unions have expressed their support to the government.

The Australian Workers Union recently put up an ad to target the mining leaders to reconsider agreeing on the tax.

“Let the mining bosses know it's time to put something back." the advertisement says.

The Mineral Council will also put up its own ad campaign to address the issues on the super profit tax but will not target marginal seats.

Treasury Wayne Swan told media over the weekend that several miners privately admitted that they can pay more taxes but did not reveal their names.