Australia's prime minister has proposed making all lawmakers prove they are not dual citizens in a move that could threaten the stability of his own government.

The High Court last month disqualified five lawmakers, including two government ministers, because they breached a 116-year-old constitutional ban on foreign citizens sitting in Parliament, creating an unprecedented political crisis.

Prime Minister Malcolm Turnbull said his Cabinet decided on Monday that all lawmakers should provide evidence to Parliament that they're not dual citizens.

Turnbull has previously resisted calls for added scrutiny of lawmakers' citizenship status. His critics say he fears losing more lawmakers because of his government's precarious control of Parliament.