The Senate has torpedoed tough new regulations which stripped away visas from migrants who provided false or misleading information on their application forms.
A Greens disallowance motion passed the upper house on Tuesday 31-29, with the support of Labor and the Nick Xenophon Team senators, repealing the regulations which also covered mistakes on applications.
Under the regulations, which , anyone who submitted false or misleading material as part of a visa application - even unwittingly - faced being effectively barred from making a new application for 10 years.
The previous penalty was just 12 months.
Greens senator Nick McKim said Immigration Minister Peter Dutton's changes to visa regulations were "disproportionate, draconian and punitive".
He said people who had done nothing wrong or been defrauded by migration agents risked being detained or deported.
"People could have been detained for falling sick when they are poor," Senator McKim said.
One Nation leader Pauline Hanson said the Greens' concerns were exaggerated and if people did not follow the rules they should not be allowed into the country.
"We have allowed too many people in this country who are abusing us, taking us for granted and taking us for mugs," Senator Hanson said.
Effectively the dumped regulations would have meant anyone who submitted incorrect information as part of an Australian visa application could have been barred from reapplying for a decade.
This would have included inaccurate statements, omissions of fact, or lodging bogus documents such as bank records, work experience claims or false English language proficiency scores.
When the proposed changes were announced an immigration law specialist told SBS News the impact would have been 'devastating'.
"[It] would have quite a devastating impact on any migrant who breached their rule of perfection in any manner whatsoever," Mary Crock, an immigration law specialist at the University of Sydney, said.
"If you're denied that long then it's going to become impossible to come to the country."
Mr Dutton's office has been contacted for comment.