Parliament approves PNG processing centre

The Howard government-era processing centre on Papua New Guinea could be open within weeks.

The first asylum seekers are set to be transferred to Papua New Guinea within weeks after the federal government successfully established the country as a new regional processing hub.

Parliament's lower house on Tuesday approved a legislative instrument that ultimately paves the way for the re-opening of the Howard government-era processing centre on Manus Island.

Immigration Minister Chris Bowen said it was another step forward in the campaign to stop people smugglers.

"Approving this designation will reinforce regional processing arrangements already underway in Nauru and illustrate the government's resolve to discourage dangerous boat journeys to Australia," he told the parliament.

Up to 600 asylum seekers are expected to be sent to the Manus Island facility, which was originally shut down by the Rudd government in 2008.

Mr Bowen said the first transfers were expected to occur within coming weeks.

The coalition supported the move to recognise PNG as Australia's second offshore processing option but didn't pass up an opportunity to remind Labor it was their idea in the first place.

"It's always been our policy," opposition immigration spokesman Scott Morrison said.

Mr Bowen is adamant the government's new policies are working, noting some asylum seekers have opted to return home since transfers to Nauru began.

"These returns represent a powerful message which undermines the viability of the people smuggler's model," he said.

Australian Greens MP Adam Bandt proposed an amendment seeking to limit detention on PNG to 12 months, but it was soundly defeated, with only Mr Bandt and independent Andrew Wilkie agreeing with the measure.

They were also the only two to vote against the government's motion.