The government lifted the threshold at which the MRRT would apply to $A75 million, in a move to secure the vote of independent Andrew Wilkie.

It was the final vote required by the government to get its legislation through the lower house later this week, after fellow independents Tony Windsor and Rob Oakshott formally backed the tax yesterday.

In a statement, Wilkie said he would support the controversial mining tax after securing what he believed was a better deal for the junior miners.

The deal includes a lift in the threshold at which the tax will apply from $50 million to $75 million and to phase in a further increase to $125 million.

“The MRRT needs to also be fair to business and the $50 million threshold and depreciation provisions in the bill patently favour the big miners over the smaller companies,” he said.

Wilkie said the lift in the threshold to $125 million was expected to cut the number of resource companies paying the full rate of the tax to 20-30.

However, he said he was unable to renegotiate the depreciation provisions.

The change in policy is expected to cost about $100 million over the forward estimates.

The move angered Greens leader Bob Brown who previously said the Greens would not back proposals limiting the revenues that could be raised from the tax.

Asked yesterday whether the Greens would withdraw their support for the bill, Brown said it would need to be revenue-neutral in order to gain support from his party.

“Andrew Wilkie may go that way, we will hold our position,” he was reported as saying.

“We will no doubt be talking about this with the government in the coming day or two.

“It’s up to them to make this a revenue-neutral arrangement.”

Brown previously flagged that the proposed tax should be expanded to include uranium and gold.

This story first appeared on ILN's sister publication Miningnews.net.