Qantas chief Alan Joyce has rejected suggestions the airline has done an about-face over the impact of the carbon price, after issuing two apparently contradictory statements about the scheme this week.

The debate has prompted questions about whether the airline has come under pressure from the Government - something Prime Minister Tony Abbott has vehemently denied.

A political row has erupted since Qantas announced a half-year loss of $235 million and the axing of 5,000 jobs.

The Federal Government responded by vowing to lift foreign ownership restrictions and calling on Labor to help repeal a carbon tax it says is shackling the airline.

On Monday, Qantas issued a statement dismissing a claim that the carbon price was a "key issue".

It was posted on its website just before the Federal Government announced a Cabinet decision to push ahead with lifting legislative restrictions on Qantas instead of granting it a debt guarantee.

It elicited a rebuke from Treasurer Joe Hockey who said he was "surprised" and noted that Qantas paid $106 million to cover the tax last financial year.

But today, the airline has issued a fresh statement, saying that the carbon price "is among the significant challenges we face" and revealing that it has paid $59 million in carbon tax so far this financial year.

In his first public comments since the Government announced its decision, Mr Joyce says the airline's position on the carbon tax has always been "very clear".

"It is absolutely one of the factors that's impacting the airline, along with the fuel price," he told a business forum in Sydney.

"There was some commentary, maybe misunderstanding out there, about what our position was on this.

"What we issued today was just a normal daily clarification that we're making on everything that we do.

"It's not inconsistent with what we've said before. We've always had the same view on what the carbon tax situation has been for us as a company."

Mr Joyce did not answer a question about whether he had been asked by the Government to provide more support for axing the carbon tax.

Questions raised over pressure on Qantas to change stance

Mr Hockey says he is not aware of any pressure being exerted on Qantas to change its stance from senior Government ministers.

"That's a matter for the company; that's a matter for them," he said.

"I'm not going to second-guess the company."

The Prime Minister's media office has been distributing today's clarification to journalists.

In Question Time, Opposition Leader Bill Shorten pursued Prime Minister Tony Abbott over whether he or his office had called on Qantas to change its position.

The Prime Minister called the question a "smear".

"There has been no contact whatsoever between me and my office and Qantas along the lines that the Leader of the Opposition suggests," he told Parliament.

In today's statement, Qantas also notes that the Government's move to repeal the major section of the Qantas Sale Act is in line with the airline's long-term wishes, but says "if the legislation does not pass, then the domestic distortion would remain".

Opposition accused of 'playing games'

The Senate is unlikely to pass the amendment even when the Greens lose the balance of power and new micro-party senators take their seats in July.

But Greens leader Christine Milne has accused the Opposition of "playing games".

"Stop messing about here," Senator Milne said.

"If they are serious about saving jobs here, if they're serious about keeping maintenance here in Australia... then stop playing games and get behind the Greens motion."

Earlier today, Mr Abbott revealed that Qantas had asked for a $3 billion unsecured loan.

He said Cabinet rejected the request - and the suggestion of a debt guarantee - after receiving expert financial advice.

Transport Minister Warren Truss says Qantas is not in imminent danger of failure, with around $2 billion of cash at its disposal.

The Opposition, which said it would have given Qantas a debt guarantee, has called on the Government to release the advice it received.

Union leaders have sat down with Qantas management again this afternoon in Sydney to discuss the airline's plans to slash jobs.

ACTU secretary Dave Oliver says the meeting was disappointing and Qantas has still has not given them any clarity about which jobs will go.