The Turnbull government needs eight crossbench votes in the upper house to get its company tax plan through parliament, but has only got four votes so far.

“We have not yet been able to secure the necessary support,” Finance Minister Mathias Cormann told reporters today, the last day of parliament before the winter break.

“We need more time to make our arguments to our colleagues on the Senate crossbench.”

The Coalition wants to cut the tax rate for businesses with turnovers of more than $50 million a year from 30 per cent to 25 per cent.

Cormann said the government is committed to the tax cuts, but they won’t come back to parliament until after the five July 28 by-elections.

“Who knows? We might have a more business-friendly Labor leader, all sorts of things could be different after the by-elections,” Cormann said.

He declined to answer a question as to whether One Nation senator Pauline Hanson had indicated she may be more open to supporting the tax cuts after Queensland’s Longman by-election which her party is contesting.

Labor is opposed to the business tax cuts, and has been pressuring Hanson hard not to vote for them.

Hanson, who controls two votes, appears to have hardened her regularly-shifting stance, telling the government to take the package to an election.

“We very much urge One Nation not to cave at the last minute,” Labor frontbencher Tanya Plibersek said before the government announced the hold.

The two Centre Alliance senators oppose the cuts and they haven’t budged for months.

Centre Alliance candidate Rebekha Sharkie is contesting a by-election in her South Australian seat of Mayo, where support for a company tax cut sits only at about 25 per cent.

Hinch and fellow independent Tim Storer also remain opposed.

Cormann said the government would keep negotiating with senators, including cracking down further on multinational tax avoidance to appease Hanson.

The company tax cuts can return to parliament on August 13 at the earliest.

– AAP