Pauline Hanson says the three votes of her One Nation senators are not guaranteed in supporting the government's planned company tax cut.
The Queensland senator would rather see payroll tax cut, because she says it's stifling growth and employment.
"It is a stupid tax, the more people you employ, the more you pay on wages, the more you get hit with taxes," she told ABC TV on Sunday.
She has raised the matter with Treasurer Scott Morrison, who said he had spoken with the states - who administer payroll taxes - but they wouldn't play, Senator Hanson said.
She was also concerned about the ongoing impact on the budget.
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"If you think I'm going to give a company tax (cut) and then a few years down the track, they are saying, 'Hang on a minute, we haven't got enough money to run the country or we can't lower our deficit, we are going to increase the tax on all Australians for five per cent' ... I will not support that," she said.
Asked if all that added up to her not supporting the company tax cut, she said: "It's not guaranteed, no."
