In August, former prime minister Malcolm Turnbull dumped the controversial plan to slash the corporate tax rate for large businesses from 30 to 25 per cent.

Despite the policy once forming a key plank of the government's economic agenda, it's not going to return if the coalition wins the May 18 federal election.

"I can absolutely rule that out. Absolutely 100 per cent," the prime minister told reporters in Port Macquarie on Thursday.

"We will not be increasing or reducing taxes for businesses of more than $50 million in the next term of parliament."

Mr Morrison said he had not discussed the issue with potential crossbench senator Clive Palmer, who was in favour of the cut, or United Australia Party officials.

"Never had a discussion with the UAP about it. Weren't looking to have one. They didn't ask for one," he said.

"So that is an absolute thing I can categorically, completely rule out."

Labor will attack Mr Morrison over the aborted policy in a new advertising campaign with clips from his time a treasurer.

"We are pursuing our enterprise tax plan, nothing's changed on that," he says in the old footage.

"We remain committed to this, see we don't flip and flop around these things."

Australian Associated Press