A former Nauru justice minister, Mathew Batsiua, says a rally is being planned because of growing public anger at the lack of scrutiny on government activity.
For nearly a year there has been no effective opposition in the parliament with five of the opposition MPs suspended.
Legal moves by the MPs to get their seats back have failed and attempts to negotiate their return have come to nothing.
Mathew Batsiua, one of the shut out MPs, says the people are becoming increasingly angry at the absence of checks and balances on government.
"So people are crying out for parliament to restore members of the opposition, so we can have decent parliament sittings, where the activities of government, the policies of government are properly scrutinised by parliament. So people want to see opposition members back in parliament debating policy, debating laws and having our parliament operate normally as a democratic parliament."
Mathew Batsiua says any rally could be constrained by new laws that have placed curbs on public protests.