Liberal frontbencher Alan Tudge has confirmed the government is "taking a look" at imposing a cap on its flagship company tax cuts.
Key crossbench senator Derryn Hinch has suggested giving tax relief to companies with turnovers of up to $500 million (excluding the banks) to jimmy the log-jammed plans through parliament.
"We're taking a look at this, but as you know, the prime minister and the treasurer have said that we're fully committed to our corporate tax plan," Mr Tudge told Adelaide's 5AA radio on Wednesday.
"The reason being that it does create investment which then leads to jobs, so we're taking it back to the parliament as it is."
Treasurer Scott Morrison has conceded the corporate tax cuts are politically difficult for the Turnbull government but remains adamant the policy will help the economy.
Mr Morrison stopped short of promising to take the corporate tax measure to the next election, but said the coalition was sticking with them.
"It's the right economic policy. The politics is a separate issue. Governments always have to manage politics," Mr Morrison told ABC radio.
Backbenchers are urging the government to put the cuts to a vote in the Senate and let them fail, to deprive Labor of one of its strongest attacks.
Mr Morrison wouldn't be drawn on whether the government would dump the policy if it was voted down in parliament, saying coalition MPs still backed tax cuts.
Liberal backbenchers Tony Pasin and Jim Molan have questioned the timing of the policy after revelations of misconduct in the banking sector.
"By doing it now at the same time as the royal commission, we're making a rod for our back," Senator Molan told 2GB.
But the treasurer pointed to the government's levy on the major banks, saying the money raised from the tax was being funnelled into education.
"The banks will always be paying more tax than other companies in this country," Mr Morrison said.
Senior cabinet minister Peter Dutton said Labor had effectively used the policy against the coalition in the Longman by-election on Saturday.
"We shouldn't give them the ammunition to throw back at us," he told the Seven Network.
Mr Morrison said the tax package - which aims to cut the tax rate from 30 per cent to 25 per cent for companies with annual revenues above $50 million - will go to the Senate next month.
One Nation and Centre Alliance senators remain opposed to the plan, meaning the draft laws are unlikely to get through the upper house.
Finance Minister Mathias Cormann warned Senator Hinch's proposal would be counterproductive.
"If you put a cap at which essentially a higher company tax rate would kick in, you provide a perverse incentive for bigger businesses to become smaller businesses," Senator Cormann told Seven.
