But Treasurer Wayne Swan today said the tax would not be on the summit’s agenda because the government was in the process of designing the measure and preparing legislation for parliamentary approval.
“That’s the first time I’ve heard of that,” Mr Windsor told ABC Radio in response to the mining tax’s omission.
“I thought it was going to be included in any discussions in relation to taxation and the Henry review.”
But Mr Swan told the ABC: “I am involving all members of the Parliament, including the independents, in the discussion.”
Mr Swan said Labor was committed to the tax, and a panel chaired by former BHP Billiton chairman Don Argus was looking at it in greater depth.
“Tony Windsor and the independents will have views about the design of that tax, which they can express to the government but we have to move forward with legislation.”
The opposition says the agreement that secured a Labor minority government had failed at the first hurdle.
“Labor is already sliding away from the deal they made with the country independents,” opposition frontbencher Christopher Pyne told ABC Radio.
Mr Swan later told reporters in Canberra he had held productive talks with Mr Windsor about the tax in the past.
“Tony has some views and wants to be consulted on the MRRT and would [in the] in normal course of events anyway, irrespective of anything we’ve agreed to,” he said.
Mr Swan acknowledged the government needed to win over key crossbenchers in both houses of Parliament to have the tax enacted.
He also said he would not prevent recommendations from the Henry tax review that were previously rejected by the government from being discussed at the summit.
Any new legislation, especially as important as the MRRT, involved a process that took some time and rarely less than six months, Mr Swan said.
“Whether it can be done and into legislative form at the end of this year, I couldn’t tell you.”
With the government still in caretaker mode, the Argus committee has not been operating fully but it could now restart.
“To some extent we are in the hands of the time that the Argus committee takes,” Mr Swan said.
“But we will be seeking to do it as quickly as we can consistent with making good public policy.”
There would be extensive public consultation as a matter of course.
Mr Swan rejected suggestions that most of a $10 billion deal Labor negotiated with the country independents in return for their support would come from tax.
Nationals leader Warren Truss has claimed about $6 billion would come from the mining tax.
“Fair dinkum, when it comes to numbers you can’t listen to the Liberal Party or the National Party,” Mr Swan said, adding that only $500 million would be funded from the tax.
Mr Swan said he did not plan to put off introducing legislation for the tax until the second half of next year, when the Senate would be more favourable for Labor.
Until then, Family First Senator Steve Fielding and the Coalition would be able to block the new resources regime.
“I would like to get this into legislative shape as quickly as we possibly can,” he said.
“There’s no notion in my mind of delaying the considerations that are so important to this tax until we get a change in the Senate, just none.”