Finance Minister Mathias Cormann has accused a Labor MP of making the "recklessly irresponsible" claim that the Australian economy is in recession.
West Australian MP Anne Aly used the assertion to argue against the full tranche of the government's full tax plan, later softening her language to say a recession "could be on the cards".
"What about the fact that our economy is in a recession, or it looks like it's going into a recession," she told Sky News on Wednesday.
"Maybe a recession is a big thing to say, but certainly the economy is not doing as well (as the government says).
"A recession could be on the cards and I think it's something we need to talk about and take into account when making decisions."
But Senator Cormann says the claim is "recklessly irresponsible and wrong".
"They show that Labor has learnt absolutely nothing from the recent election outcome," he said in a statement.
"Importantly, higher taxes and the politics of envy, which Anne Aly still appears to be advocating for, would make our economy weaker."
Senator Cormann has ruled out bringing the next sitting of parliament forward a week to legislate the promised tax cuts by the end of this financial year.
He said there was no practical difference between that timing and the July 2 parliament opening already scheduled.
"People will only be able to lodge their tax returns from 1 July and, as long as the parliament passes our income tax relief plan in full swiftly, the first week of July the tax office will be in a position to process the tax returns and put more money into people's pockets."
Despite the looming change, the minister said Australians should file their tax as they usually would.
The Australian Taxation Office has said it can retrospectively amend tax assessments to provide cuts if the laws passed after June 30.
The new parliament is set to convene on July 2 for three days, however, the first day is usually consumed by ceremony.
The coalition is yet to lock in the support it needs from Labor or at least four crossbenchers in the upper house to get the three-stage tax package across the line.
Labor supports the first stage of the $158 billion plan, which will mean extra cash for low and middle income-earners.
But it believes the later stage, aimed at flattening the tax rates by mid-2024, shouldn't be legislated years in advance and may be skewed toward the wealthy.
The coalition has ruled out splitting up the plan, arguing the final stage brings much-needed structural reform and that its election win has given it a mandate to bring to all of the changes to life.
The opposition has called for more detailed information about how much of the package will benefit those earning more than $180,000.
But Senator Cormann says the budget papers are detailed enough.
One Nation leader Pauline Hanson, who directs two Senate votes, has said she won't back the plan because major infrastructure spending would be a better way to stimulate the economy.
Centre Alliance, which also has two votes, remains on the fence, amid concerns the extra cash for workers could be lost to rising power costs.
Australian Conservatives leader Cory Bernardi is expected to side with the coalition and independent Jacqui Lambie says she is "consulting widely".
© AAP 2019