Greens slam refugee bill as dangerous

A person with a 49 per cent chance of being tortured could still be sent home under sweeping changes to the way asylum seekers are processed.

The change to the risk threshold for people seeking protection under international conventions against cruel and inhuman punishment, including torture, is part of a bill introduced into parliament by Immigration Minister Scott Morrison on Wednesday.

The Greens are scathing of the move, calling it an ideological and dangerous attack on vulnerable asylum seekers already in Australia.

Mr Morrison said the government remained committed to abiding by its international obligations.

The Federal Court had found the threshold for accepting a claim not to be returned was a "real chance" of significant harm.

However the government believed the threshold should be "more likely than not" - meaning a greater than 50 per cent chance a person would suffer significant harm in their country of origin.

"This is an acceptable position which is open to Australia under international law and reflects the government's interpretation of Australia's obligations," Mr Morrison said.

The change is one of several that toughen the way asylum seekers are assessed, leading to "enhanced integrity measures and increased processing efficiency".

The changes include requiring applicants to establish their reasons for claiming refugee status upfront, rather than at review.

Rules covering identity are also being tightened.

Mr Morrison said identity was increasingly complex to determine, and many people held multiple nationalities or tried to hide their identity.

Under the proposals, a protection visa will usually be refused unless applicants provide documentary identity evidence.

Bogus or destroyed documents will also mean visas are refused.

And the bill stops those on protection visas including their relatives, who will have to use the family migration "pathway".

Greens Senator Sarah Hanson-Young said the legislation aimed to reduce the number of refugees Australia resettled and set up the framework to deport people back to danger.

"If you can't prove that you are more likely to be shot than not, then you will be on your way home," she said.