Bill Shorten has confirmed a future Labor government won't place any time limits on how long asylum seekers can be held on Manus Island and Nauru.
Labor is preparing to debate offshore detention at its national conference in July, with a draft party platform calling on a Shorten government to "strive to ensure (detention) is for no longer than 90 days".
Asked whether the proposal would extend to asylum seekers detained offshore, the Labor leader told reporters in Brisbane on Tuesday: "The answer to that is no."
Prime Minister Malcolm Turnbull has suggested supporting such a limit would be "rolling out the welcome mat to the people smugglers".
Mr Shorten insisted his party would not "start the boats again" or put people smugglers back into business.
However, he argued the Turnbull government must work harder to ensure people are not placed in indefinite detention.
"The more positive approach we would adopt is putting more energy into resettlement," Mr Shorten said.