In surprisingly frank comments set to deepen antipathy between Mr Morrison and the Liberal Party's conservative right faction now led by Mr Abbott, Mr Morrison, who had been shadow immigration minister, said the rejection in the Senate of the Labor government plan to stop the boats, was down to Mr Abbott alone.

"I acted in accordance with my leader's instructions," Mr Morrison told Sky News when pressed on the reason the opposition had refused point-blank to legislate the scheme at the time.

After the High Court ruled its first incarnation was invalid, the Labor government had sought opposition or Greens support to pass enabling legislation in the Senate.

Both refused.

The arrangement signed off with the Malaysian government would have seen a random selection of up to 800 asylum seekers who arrived by boat, transported to Malaysia in exchange for Australia settling 4000 accredited refugees.

The government was acting in accordance with the best advice from the Department of Immigration, which said the scheme would act like a "virtual towback".

Citing that advice, Labor argued asylum seekers could not be sure of staying even if they overcame all of the perils of a long sea voyage and made it to the mainland. Some would end up back where they had started, having lost the thousands of dollars paid to people smugglers.

Yet despite strenuous government pleas at the time and significant concessions sought and granted, the Abbott opposition remained utterly defiant, condemning the arrangement outright as ineffective and as inhuman.

A succession of Liberals welled with tears as they spoke of children suffering and of conveying to relatives news of family members lost at sea.

Yet some 582 boats carrying 38,890 souls came to Australia in the aftermath of the Malaysian deal's demise, resulting in far more suffering and perhaps more than 600 asylum-seeker drownings from vessels that failed to make it.

Last week, Mr Abbott stunned the political community by admitting the decision to block the Malaysian proposal may have been a mistake. He told a forum in Adelaide that even though he still harboured doubts about whether it could have worked, its frank rejection had exacerbated the hyper-partisanship in those years and that such an atmosphere persisted to this day.

"I wonder, though, about the former government's people-swap with Malaysia . . . I doubt it would have worked" he had said.

"Letting it stand would have been an acknowledgment of the government-of-the-day's mandate to do the best it could, by its own lights, to meet our nation's challenges.

"It would have been a step back from the hyper-partisanship that now poisons our public life."

Responding to Mr Morrison's most recent comments, a spokesman for Mr Abbott simply denied the suggestion that the then opposition leader had given orders to his hardline immigration spokesman.

"The speech didn't say that our decision on the people-swap was wrong, it said it had been a line-ball call," the spokesman said.

"And like all policy decisions, it was a team effort."

The airing of this difference is the latest expression of deep tensions within the government between the conservatives loyal to Mr Abbott on the one hand and Mr Morrison, whom they accuse of abandoning the former prime minister last September in exchange for promotion to the Treasury portfolio under Malcolm Turnbull's new leadership.

Labor's inability to stop the surge of boat arrivals was a key factor in the bitter uncompromising politics of the Gillard term, with the Coalition prosecuting a relentless attack over each arrival and charging that the government had created a porous northern maritime border over which it had relinquished any effective control.

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