Personal income tax cuts worth billions of dollars are set to pass today, with One Nation confirming it will support the Federal Government's $144 billion package and Centre Alliance conditionally backing it.

Key points: One Nation and Centre Alliance senators have indicated they will back the Government's personal income tax cut package in full

Yesterday the Senate passed the first two stages of the plan, but the Government refuses to split the bill

The final vote is expected in the Senate later today

One Nation leader Pauline Hanson told AM her party would back the entire three-stage, seven-year plan.

"Yes we are supporting the personal tax cuts … we are pleased to do so," Senator Hanson said.

Senator Hanson conceded it was "a bit of a gamble" to support the income tax cut package in full because she had previously argued the third stage was unaffordable, however the senator said she was now more optimistic about the future.

"[The third stage] not coming in till 24/25, six years down the track," she said.

"Hopefully the Government is actually getting the budget back into surplus."

In her negotiations with the Government, Senator Hanson suggested the Coalition could find more money by cracking down on multinational companies not paying their fair share of tax and reviewing the salaries of bureaucrats.

$144b income tax cut package edging closer to reality

The Federal Government has been working to secure the support of eight crossbench senators to pass its personal income tax cut package in full, because Labor wants to split the bill.

Yesterday the Senate passed the first two stages of the plan, but the Government will use its numbers in the House of Representatives to reject that offer and instead bring on an all or nothing vote.

With One Nation now on the Government's side, it needs one of the two Centre Alliance senators to come onboard.

Centre Alliance Senator Stirling Griff said his party was not in favour of the whole tax package, but would vote for it if the Government refuses to split it into chunks.

"If the Government comes back with that and they say it's all or nothing, we are certainly not going to stand in the way of low to middle-income earners receiving tax cuts, which would indicate that we more than likely will have to support the complete package," he told AM.

Centre Alliance senator Rex Patrick defended voting for the entire package even though his party did not support all of it, saying that otherwise lower income earners who would benefit from the first two stages would miss out.

He conceded that Centre Alliance's Lower House candidate Rebekha Sharkie, who is contesting the South Australian seat of Mayo, is strongly opposed to stage three of the plan which applies to high-income earners in seven years time.

"She feels quite strongly about stage three," Senator Patrick said.

He said Centre Alliance did not negotiate anything extra with the Government in exchange for its position on the income tax plan.

The art of negotiation

Senator Hanson recalled the frantic nature of the negotiation process as the Coalition and Labor tried to win her over.

"I've had a revolving door, I've had telephones, I've had them on their knees begging me, but as I've always looked at legislation, I look at it based on what is right for the country and the people," she said.

Finance Minister Mathias Cormann has been quietly working behind the scenes to try and secure the final three votes the Government needs to get its package across the line.

With the support of One Nation and the likely backing of the Centre Alliance Party, it appears he has succeeded.

During negotiations on the Government's company tax plans, Senator Hanson struck a deal with the Government to set up an apprenticeship pilot program to create 1,000 taxpayer-funded apprentice roles.