Finance Minister Mathias Cormann is not counting his chickens on income tax cuts despite a key pairing of crossbench senators indicating they will likely support the federal government's package.
Senator Cormann, who leads government negotiations in the upper house, is not getting ahead of himself after Rex Patrick said "if forced" he and Centre Alliance colleague Stirling Griff would likely back the full plan.
"I don't ever take anything for granted," the minister told Sky News on Friday.
Treasurer Scott Morrison, campaigning in the southeast Queensland seat of Longman, was upbeat about the prospect.
"I'm pleased more of the crossbench are supporting our plan for lower taxes," he told reporters.
"The only disappointment is the Labor party are for higher taxes."
Labor wants the package split to provide relief for low and middle-income earners from July 1 but not deliver the remainder, which is due to benefit those on higher incomes from 2022.
The Greens oppose the package outright.
Senator Patrick said he was inclined to split the bill and support the low-income tax cuts but if push came to shove he would likely back the entire proposal.
The finance minister is focusing his efforts on courting crossbench support, with the government appearing to be one vote short of passing the package.
"Everybody knows the numbers - we've got 31 coalition senators in the Senate, we need 39 to pass legislation which Labor and the Greens oppose," Senator Cormann said.
"There are 10 crossbench senators so we need to persuade eight out of 10."
Maverick One Nation senator Brian Burston, who has fallen out with his leader Pauline Hanson and colleague Peter Georgiou, has signalled he is on board with the plan without amendment.
It is understood senators David Leyonhjelm, Cory Bernardi, Fraser Anning and Derryn Hinch are also supportive of the package as it stands.
However, independent Tim Storer and senators Hanson and Georgiou want it split.
The cuts from July 1 would see a low and middle-income tax cut offset introduced, worth up to $530 for individuals, and the 32.5 per cent threshold increased from $87,000 to $90,000.
Stage three of the plan would increase the top 45 per cent tax rate threshold from $180,000 to $200,000 while abolishing the 37 per cent tax rate, leaving all taxpayers earning between $41,000 and $200,000 on a rate of 32.5 per cent.