Bipartisanship has broken on the live sheep export industry with Opposition leader Bill Shorten calling for a suspension until the review into the northern summer trade ordered by the government reports.

Up to now, both government and opposition were anxious to stay in step.

But with mounting public outrage at the footage of cruelty and amid signs of Liberal division, Shorten said: “We believe the review is unlikely to conclude the northern summer trade is sustainable”.

He said Labor would honour its commitment to wait for its findings. But until they came, “northern summer shipments of sheep not already beyond the farm gate should be suspended.

"We are absolutely open to working with the government on bipartisan reforms, but it’s not acceptable to allow deaths and shocking mistreatment to occur just because we are waiting for a report to be handed down”.

Former Liberal health minister Sussan Ley on Thursday announced she planned to introduce a private member’s bill after the budget to “effectively phase out live sheep exports to the Middle East”.

Liberal MP Ian Goodenough – from Western Australia where a large proportion of the exported sheep come – tweeted that “Sussan Ley’s Private Member’s Bill has considerable merit, I will carefully consider the provisions in contributing to the debate on the future of the live export industry.”

Agriculture Minister David Littleproud rejected the Shorten call for a suspension.

He said the review into the northern summer trade – which is from May until October - had already started and was likely to take three weeks.

“I’m determined to make decisions on science not emotion,” he said. “I will not make a knee jerk reaction with the science three weeks away.”

That would punish farmers who had done nothing wrong.

Littleproud said Labor’s spokesman Joel Fitzgibbon had been “honourable and good to deal with”.

“I’m disappointed Mr Shorten seems to have broken away from a bipartisan approach to make a political statement”.

Nationals leader and deputy Prime Minister Michael McCormack made it clear he wanted to see the trade continue.

“I do believe in live animal export, whether it’s sheep, whether it’s cattle, whatever,” he told the National Press Club. “I believe there is a future for it. Not just for our farmers, but also for our nation. It brings export dollars into this country. It creates jobs, it creates opportunities.”

Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.