Labor has accused the Turnbull government of running scared on its push to slap harsher penalties on dodgy live exporters in the face of a backbench revolt.
The government has parked a bill which would double maximum jail terms to 10 years and impose multi-million dollar fines on people found guilty of wrongdoing.
Labor is attempting to amend the legislation, effectively mirroring NSW Liberal MPs Sussan Ley's private bill to phase out the trade over five years and ban live exports during the northern hemisphere summer.
Ms Ley's push has the support of Liberal colleagues Sarah Henderson and Jason Wood, while there is speculation others could cross the floor to end the trade.
The opposition's agriculture spokesman Joel Fitzgibbon said the government was concerned the amendments would succeed.
"How much longer is Malcolm Turnbull prepared to delay the penalty increases his government claimed were so urgent?" Mr Fitzgibbon said on Thursday.
But Agriculture Minister David Littleproud returned fire, saying the onus was on Labor to explain why the bill was being delayed.
"Labor needs to explain why it's sabotaging a bill to double penalties for live exporters doing the wrong thing," Mr Littleproud told AAP.
"This is a serious bill about all live exports. When Labor get serious about addressing this, my hand will still be out."
Labor will be four MPs down for the upcoming fortnight of parliamentary sittings, while the Nick Xenophon-aligned Rebekah Sharkie, a supporter of ending live exports, is also facing a by-election.
"It's extraordinary the Prime Minister isn't confident about defeating our amendments and won't allow the vote to be brought on," Mr Fitzgibbon said.
Meanwhile, animal activists are taking the federal government and an export company to the Federal Court to block an export permit for a Middle East-bound ship.
A load of 58,000 sheep left Western Australia last week on board a WA-based Emanuel Exports ship headed for the Middle East.
But Animals Australia argues the export licence granted by the Department of Agriculture is unlawful.
"You've got the science saying, you've got the peak veterinary body in this country saying, that these shipments shouldn't occur because of the heat stress implications and yet permits are being granted," Animals Australia's Lyn White said outside court.