Malcolm Turnbull is set to deliver on the central plank of his 2018 budget, a seven-year personal income tax plan, despite the efforts of Labor and the Greens to block it.
On Thursday, Labor was seeking to head off the third part of the $144 billion package using tactics in both parliamentary chambers.
The opposition succeeded in the Senate on Wednesday to amend the draft laws to remove the third stage – which benefits people earning up to $200,000 from 2024 – but the coalition restored it in the lower house on Thursday morning.
Treasurer Scott Morrison told parliament step three simplified and flattened the tax system by abolishing the 37 per cent tax bracket entirely, reducing the number of tax brackets from three to four.
“The plan is a package that gives certainty to Australian families that they will keep more of what they earn in the future,” he said.
Manager of Opposition Business Tony Burke said the government was trying to gag debate on the legislation.
“When you outsource your economic policy to Pauline Hanson, careful what you wish for,” Mr Burke said.
The One Nation leader confirmed on Thursday morning her two-senator team would support the government’s full seven-year plan.
A vote is expected before noon.
Senator Hanson conceded it was a gamble to support the entire package, having previously argued the third and final stage was unaffordable but said she was now more optimistic.
“I’ve actually now decided to support the government in the tax cuts which the Australian people need,” Senator Hanson told reporters.
“It was the only fair thing to do.”
With the Centre Alliance’s two senators expected to also support the full package the coalition will have the eight Senate crossbench votes needed to pass it.
In the Senate, Labor and the Greens voiced their anger about the way in which the government had shut down debate.
Labor’s Penny Wong said it was all about the coalition’s “political timetable”, ahead of five by-elections on July 28, rather than sound policy or fairness.
Recent polls have shown a majority of voters disagree with the tax cut for the most wealthy but support the first two parts of the package.
Labor frontbencher Doug Cameron tore shreds off One Nation for siding with the government.
“This decision by Pauline Hanson to support some of the highest income earners in the country just demonstrates how out of touch Pauline Hanson is,” the senator told reporters.
Under the first of three stages in the plan, low- and middle-income earners would get tax relief of up to $530 a year from July 1.
Independent Senator Tim Storer issued a scathing attack on the Centre Alliance party, formerly the Nick Xenophon Team, of which he was once a member.
He said the minor party’s two senators had sided with the government to guillotine debate, soon after voting to scrap the package’s final stage.
“Today, Centre Alliance turned its back on the principles central to Nick Xenophon and the party he started,” Senator Storer said.