The level of support among MPs for banning live sheep exports could be tested as early as Thursday.
Senior opposition MP Joel Fitzgibbon has told parliament he will introduce an amendment to government legislation that would ban the summer trade as soon as possible before ultimately phasing out the live sheep exports.
He revealed his intention while supporting Turnbull government legislation to introduce harsh new penalties for exporters who put profits before animal welfare.
The proposal was like saying it's not OK to leave three dogs in a car in the searing heat but two dogs were fine, he told parliament on Wednesday night.
"It's not too good for the two dogs that are still left in the car - the outcome is the same," he said.
He's expecting to move the motion on Thursday and says while he could have done it as a surprise, he wanted government MPs to have a night to sleep on the proposal.
Mr Fitzgibbon's amendment would institute the same changes as are being proposed by Liberal MP Sussan Ley in a private member's bill.
"It will put a stop to the summer trade at the first immediate opportunity and it will phase out the live sheep trade over a five-year period," he said.
"I do ask members tonight to have a think about that."
So far, Sarah Henderson and Jason Wood are the only government MPs to publicly back Ms Ley's bill.
West Australian Liberal MP Rick Wilson warned if the amendment got up exporters would see there's no future in Australia and almost immediately withdraw ships and capital.
"To say that we'll phase out the industry over five years and somehow we'll adjust ... is a complete furphy," he said.
Fellow WA Liberal Nola Marino said shutting the industry down would have a "massive impact" on the state, forcing people out of sheep production and potentially collapsing sheep prices.
Nationals MP Damian Drum said it would be easy to make decisions in Canberra to ban the industry without understanding the true human cost.
If the amendment doesn't get the support to pass, Labor will still support the legislation in its original form.
Introducing the changes last week Agriculture Minister David Littleproud said individuals who break the law would feel the "full force" of prison terms up to 10 years.
Penalties also include fines of at least $4.2 million for companies and $2.1 million for individuals.