Senior ministers, including Mr Morrison, have rebuked Mr Abbott who's called for Australia's permanent migration intake to be cut to 110,000 a year, from 180,000.

Mr Morrison warned on Tuesday this would wipe up to $5 billion off the budget over four years, prompting Mr Abbott to claim his former minister had been "captured" by Treasury thinking.

On Thursday Mr Abbott went further and used Facebook to say he never accepted Treasury "orthodoxy" that immigration is good for growth.

"Scott should have the gumption to think for himself," Mr Abbott wrote.

Mr Abbott also claimed he spoke to Mr Morrison, his then-immigration minister, about making cuts under his coalition government.

"Scott Morrison has conveniently forgotten the very vigorous discussion about cutting immigration that took place inside government in early 2015 as part of the budget process," he said.

"Because we were achieving a reduction anyway I eventually decided not to adjust the official figure but I kept it on the table as I never accepted the Treasury orthodoxy that more migrants meant more growth and a stronger budget outcome."

If Treasury was right, he reasoned, "why not solve the deficit simply by ramping up immigration"?

Earlier on Thursday, Acting Prime Minister Mathias Cormann defended Mr Morrison against Mr Abbott's initial attack.

"Tony Abbott is wrong. To criticise the experts and say that somebody who is not an expert knows better is not the right approach," Senator Cormann told ABC radio.

His cabinet colleague Steve Ciobo rejected Mr Abbott's claim immigration was driving up house prices, as a "palpably absurd statement".

It was a great shame to often see immigrants having "the finger of blame" pointed at them.

"I could not disagree more strongly with Tony Abbott's comments," he said.

Australian Associated Press