Until then, he will continue to fight for the rights of asylum seekers here in Australia.

Up to 5000 people are expected to join him in Civic Square next to the ACT Legislative Assembly at a Palm Sunday rally calling for an end to mandatory offshore detention.

Protesters will also call for the Australian government to resettle asylum seekers imprisoned on Manus Island and Nauru here in Australia.

Mr Husseini witnessed firsthand the hopelessness felt by asylum seekers while in detention at Christmas Island, after he came to Australia by boat when he was 17.

With this week's chemical attack and US bombings expected to unleash another wave of Syrian refugees, Mr Husseini said: "This is the only chance for the refugees, for the asylum seekers to be heard."

Former ACT chief minister Jon Stanhope said there was a misconception that offshore detention was no longer an issue given Australia's 'people swap' deal with the United States.

"I don't accept that for a minute, I think that not only is there a real prospect that a number of people, particularly on Manus, will not be accepted by America, maybe none of them will, so I don't think we should be assuming that," Mr Stanhope said.

"The issue that's at the heart of this is that the policy is wrong. Just because somebody has come along and made it easier for us and saved us from our own embarrassment doesn't mean that the issue will go away.

"The policies we currently have as a nation are simply unacceptable in a moral sense and for a nation with respect to human rights."

Greens politician Caroline Le Couteur said: " The bottom line is refugees are the same as us, we need to show compassion to refugees same as anyone else in our community."

The Palm Sunday Rally will take place in Civic Square on Sunday, April 9 from 1pm.