Expanded refugee fast-track sunk in Senate

More asylum seekers will be spared from a fast-tracked processing system critics claim is unfair after the Senate voted to dump new migration laws.

Greens senator Nick McKim's disallowance motion passed the upper house on Tuesday night, repealing a move to put more boat arrivals on the fast-track.

"People in the fast-track process are not given a fair opportunity to put forward their case for asylum," Senator McKim told parliament.

"They're not given a fair opportunity to deal with the adverse information affecting their application."

The move would have applied to a "legacy" caseload of 108 people who arrived by boat before 2014 and were already living in Australia.

Cabinet minister Nigel Scullion said the legal instrument aimed to resolve asylum seekers' status.

He said it would ensure people would be removed from Australia in a timely manner where an unauthorised boat arrival was found not to meet the conditions to be granted protection.

Labor backed the disallowance motion, which succeeded 33 votes to 29.