In the speech to a Hungarian migration summit in March, which flew under the radar in Australia at the time, Mr Downer also took aim at refugees he said were "undermining the whole system" by demanding permanent settlement rather than temporary protection.

Mr Downer's lecture to the Mathias Corvinus Collegium in Budapest strongly commended integration of migrants rather than letting them live what he called a "Bantustan-style life", a reference to the segregated black settlements of apartheid South Africa.

"If you do take people as migrants, you want to make sure they integrate," he said.

"I don't really agree with the liberal left who argue that in Australia we should change the culture of our country to accommodate migrants. I think, on the other hand, migrants who wish to come to our country should endeavour to try to integrate into our community, not set up separate ghettos.

"We want them to be able to participate fully in the activities of our country, and not to have them go off and live in separate communities and live a kind of Bantustan-style life totally separate from the rest of the mainstream of Australia."

Mr Downer said Australia had an obligation to protect refugees, but only temporarily while they fled prosecution.

"When that's finished they should peacefully be able to return home," he told his Budapest audience.

"There is a world of difference between somebody who migrates to our country and somebody who we protect as a refugee.

"These people are not looking just for protection, these people are looking to migrate. And they are looking to migrate to the country they want to go to. They get protection in all sorts of other countries on the way to your country, but no, no, no - we're going to let them in and become migrants. This is, of course, undermining the whole system."

Mr Downer spoke at the MCC's Budapest Summit on Migration alongside other Australians including Tony Abbott's former international affairs adviser Mark Higgie and University of Queensland law professor James Allan.

Ultra-conservative Hungarian Prime Minister Viktor Orban also addressed the conference, as did former French president Nicolas Sarkozy and former Czech president Vclav Klaus.