Business tax cut plan stuck in Senate

The coalition's bid to cut company taxes is stuck in the Senate with just a day to go before parliament breaks for the winter.

The government is short of the votes it needs to get its business tax cut plan through the Senate. (AAP)

Big business tax cuts are stuck in the Senate despite heavy negotiations from the coalition, who haven't convinced Pauline Hanson to vote for them.

Thursday is the last day of parliament before the long winter break, but the government is still four votes short to getting the draft laws through the upper house.

Senator Hanson controls two of those votes, and is regularly shifting her position on cutting the tax rate for companies with turnovers above $50 million.

"I will change my mind as many times as I want to ensure that I come up with the right decision," Senator Hanson said on Wednesday.

The two Centre Alliance senators oppose the cuts and they haven't budged for months. Independents Tim Storer and Derryn Hinch also remain opposed.

But the government's chief negotiator Mathias Cormann is not giving up on getting the bill to a vote.

The Finance Minister has ruled out Senator Hinch's compromise deal limiting tax cuts to businesses with a turnover of up to $500 million, because another crossbencher David Leyonhjelm would back out.

Labor opposes the bill cutting the company tax rate from 30 per cent to 25 per cent, and Bill Shorten also plans to roll back cuts already legislated for businesses with turnovers up to $50 million.

Senator Hanson told the Nine Network she was "adamant" in her opposition to the tax package, but then said she was still negotiating.

The One Nation leader then appeared on 3AW radio to harden her stance again.

"Let them take it to the next election, let's see what the people say," Senator Hanson said.

But Labor senator Tanya Plibersek said Senator Hanson had voted with the coalition 100 per cent of the time this year.

Centre Alliance senator Rex Patrick told AAP he and his colleague Stirling Griff will not support the package unless they get a guarantee there will be no cuts to health, education and welfare as a result.

It was unclear on Wednesday evening whether the government would make the Senate sit beyond Thursday into Friday in order to give extra time for the tax cuts bill debate.

Meanwhile, the fallout continued over Mr Shorten's decision to roll back small business tax cuts.

Labor backbencher Ross Hart said it had not gone to shadow cabinet and described the policy as a "matter for Bill Shorten".

But Labor frontbencher Anthony Albanese said Mr Shorten had a "right to announce Labor policy" and had done it in a way consistent with Labor's voting position on the tax laws.