Hundreds of people rallied in Melbourne on June 25 to protest against the transfer of a young baby, Asha, to the Nauru detention centre.
The rally occurred on the same day as the federal government, with support from the Labor opposition, voted to change the law to keep the prisons on Nauru and Manus Island open to defeat a high court challenge.
Pamela Curr from the Asylum Seeker Resource Centre said: "We can defeat this criminal policy, but it won't be easy."
Dr Grant Ferguson, a doctor who gave evidence to the National Inquiry into Children in Immigration Detention, said: "We must release children from detention.
"What must it take for a six-year-old to want to self harm? These children are being denied a voice."