Treasurer Scott Morrison says he hopes Tony Abbott isn't trying to undermine Prime Minister Malcolm Turnbull, but admits the former PM's interventions are damaging the Government.

"I'm not denying the fact this stuff is unhelpful," Mr Morrison told 7.30.

"It'd obviously be terribly disappointing if that was the intent."

Mr Abbott has been increasingly critical of the Government's agenda, but the Treasurer would not be drawn on whether Mr Abbott was setting out to hurt the Government.

"It'd be disappointing if it was," he said.

"Do you think it is? You know him well," 7.30's Leigh Sales asked.

"Well I don't know Leigh. I'd hope it wasn't," Mr Morrison replied.

Home Affairs ministry dispute

Mr Abbott's most recent contribution was his claim that as prime minister he was advised against creating a Home Affairs ministry, which he described as a "massive bureaucratic change".

But if that advice existed, Mr Morrison, who was enthusiastic about creating a Home Affairs ministry when he was immigration minister, said he didn't see it.

"I didn't have any advice of that nature. What advice the then prime minister had only he could speak to," he said.

"He didn't implement one, that's the record that matters. He chose not to do that."

Mr Abbott's criticism of the change came a day after comments made by Immigration Minister Peter Dutton, who told 7.30: "I know from my discussions with Tony, when he was prime minister, he supported the concept of a Home Affairs office."