The Turnbull government is not giving up on passing its corporate tax cuts despite being four votes short of success.
Finance Minister Mathias Cormann has welcomed One Nation senator Brian Burston's support for the move to drop the tax rate from 30 per cent to 25 per cent for all businesses.
But Senator Burston's One Nation colleagues, Pauline Hanson and Peter Georgiou, remain opposed to the cuts despite previously reaching an agreement with the coalition to support them.
A split in the party isn't in the interests of the government, says Senator Cormann, who still wants to get all three One Nation senators on board.
"Obviously from my point of view it would be preferable if all One Nation senators remained committed to the consensus that we reached," he told Sky News on Friday.
With Labor and the Greens firmly opposed to the plan, the coalition needs eight crossbench votes to add to its 31 senators.
Senators Burston, David Leyonhjelm, Cory Bernardi and Fraser Anning all back the company tax cuts.
But the two Centre Alliance senators and independents Tim Storer and Derryn Hinch have yet to commit to the plan.
Labor wants to use the corporate tax cuts as a point of attack in five by-elections to be held on July 28.
Meanwhile, there's also suggestions Labor is actively considering supporting the first two stages of the government's personal income tax cuts, but fighting a third stage - not due to come in fully until 2026 - at the next election.
The opposition backed legislation through the lower house last week, but failed in its bid to split the reforms.
Fairfax reports they could support the legislation through the Senate but promise voters an overhaul.
Senator Cormann said if the reports were true the government would welcome it.