Cabinet’s national security committee last October favoured Australia’s new submarine fleet being mostly constructed overseas with the Australian Submarine Corporation (ASC) having only limited work, according to the ABC’s Four Corners.

The program was told this “by sources intimately involved with the project”.

The submarines became an issue for Tony Abbott in the run up to the unsuccessful motion to spill the leadership, when he was forced to make promises about the involvement of the South Australian industry.

It had been rumoured Abbott had given the nod to Japanese Prime Minister Shinzo Abe for Japan to get the inside running.

Coalition defence spokesman David Johnston promised in the election campaign that 12 new submarines would be built in Adelaide.

In its program “House of Cards” about the push against Abbott’s leadership, Four Corners reported that it “had been told by sources intimately involved with the project that the government’s top secret national security committee, which included key ministers led by the PM, debated the submarines in October last year.

"No final decisions were made in favour of Japan. But sources close to the discussions told Four Corners the meeting did support options for the bulk of the submarines’ construction to go overseas and for only limited work to go to the Australian Submarine Corporation.”

The decision was justified “for cost and time constraints”, the program said. “It was political dynamite and it was kept secret, even from the South Australian government.” Johnston, defence minister at the time, under instructions from the Abbott office never released the outcome of the October meeting, despite drawing up a press release.

Before the vote on the spill motion, South Australian Liberal senator Sean Edwards made his support for Abbott conditional on an assurance that Australian shipbuilders would have the right to participate in the project. Abbott satisfied Edwards sufficiently to get his vote.

Under the process finally announced, France, Germany and Japan are invited to participate in a competitive evaluation process for the subs, with maximum Australian involvement in their construction and maintenance.

Four Corners has further stirred the issue of Abbott’s chief of staff Peta Credlin. It obtained a text that Liberal party treasurer Philip Higginson sent to a senior Liberal figure late last year during his now well-aired battle to get more information on the party’s accounts. Higginson encountered resistance from Liberal director Brian Loughnane and interference from Credlin, who is Loughnane’s wife.

Higginson texted: “I do hope you can negotiate the removal of Credlin. That would be a huge win in itself. She has ‘effed’ the Parliamentary Wing thru her non understanding of team harmony … and she has ‘effed’ the Organisational Wing.

"I’m refusing to sign the 2013/14 accounts … It has brought the Horsewoman of the Apocalypse out of her den as you could imagine. Black robes flowing. Stay tuned for the hatchet job on me.”

Four Corners also reported that in the run-up to the vote on the spill motion, the National Civic Council – a Christian lobby group – orchestrated a massive email campaign to pressure MPs to support Abbott’s leadership.

NCC supporters were asked to “Please email Federal Liberal MPs and Senators to support Tony Abbott … Abbott has held the line on marriage, repealed the carbon tax and other things. Whatever his failings, the alternatives are Malcolm Turnbull, who failed as leader, and Julie Bishop, who was forced to resign as shadow treasurer”.

Liberal senator Ian Macdonald told the program that if Abbott’s leadership did not succeed he believed “Tony would do the right thing by Australia and by the party [and] see if someone else could take us to an election winning time next year”. But “I think given the circumstances he will turn it around”.