Pauline Hanson has laid out why One Nation can no longer support the Turnbull government's business tax cuts, blaming a lack of action on immigration, energy costs and encouraging firms to take on apprenticeships.
She also feels the government has not done enough to rein in spending, leaving a budget built on "eggshells" at a time when multinationals are not paying sufficient tax under the petroleum resource rent tax.
"I just feel that they are not addressing the black hole in the budget, and I have got concerns that we are not going to be paying down debt," Senator Hanson told reporters in Hobart on Tuesday.
She also cannot support the third stage of the government's personal income tax plan because it doesn't come in to effect until 2024/25.
"Australians need that support now," she said.
She confessed she had not spoken of her party's decision to Finance Minister Mathias Cormann, who is the government's chief negotiator in the Senate.
Shadow treasurer Chris Bowen said it appears the government made a series of concessions in order to get One Nation's support for the 10-year business tax cut plan.
"We should have, the Australian people should have, full access to all the information that the government has been horsetrading on in relation to policy," Mr Bowen told reporters in Canberra.
Senior Labor senator Penny Wong pursued Senator Cormann in a Senate estimates hearing over what was agreed with One Nation.
Senator Cormann said agreements, like the apprenticeship scheme, were made on the basis of securing the passage of the legislation through the parliament, but said it was "ridiculous" to suggest One Nation was setting government policy.
Asked to hand over any written agreements with One Nation, Senator Cormann took the question on notice.
With other crossbenchers and Labor opposed to the plan, the government needs Senator Hanson's votes to secure the package.
Independent senator Derryn Hinch was surprised by Senator Hanson's backflip, given One Nation was "passionately lobbying" him to back the company tax cut plan in full two weeks ago.
He likened the intensity of lobbying efforts by One Nation to those by Senator Cormann's staffers.
Cabinet minister Peter Dutton denies One Nation has killed off the package, saying negotiations are continuing.
"She is a wily operator, Pauline. She will put out there she is supporting it, she is not supporting it, she is not supporting it," he told the Nine Network.
"She understands the benefit of tax cuts in an economy like ours."
Australian Associated Press