Another split in Federal Cabinet has opened just a day after Tony Abbott threatened to sack leakers in a ministerial face-off the Prime Minister described as a "come-to-Jesus moment".

_The West Australian _understands that Trade Minister Andrew Robb is furious that his proposal to open up northern Australia to international airlines was dumped by Cabinet colleagues yesterday in his absence.

It is understood Mr Robb, who is having a back problem fixed, believes his proposal has been misrepresented inside the Government and fell victim to vested interests in the airline industry.

Treasurer Joe Hockey formerly supported Mr Robb's proposal to allow foreign carriers to fly to airports north of the Tropic of Capricorn but has backflipped.

Finance Minister Mathias Cormann is also believed to have backed Mr Robb's proposal, which would have potentially opened up Qantas and Virgin to competition on routes serving Broome, Darwin, Cairns, Karratha and Townsville on a trial basis.

Last week's astonishingly detailed leak about a Cabinet split on national security prompted the PM to tell ministers on Monday night they risked "personal and political consequences" if they breached Cabinet confidentiality.

This was interpreted as a threat to sack anyone caught leaking.

Mr Abbott told the coalition party room yesterday it had been a "come-to-Jesus moment" for ministers - a comment that prompted some MPs to look up the phrase on Google to find out what the PM meant.

One MP said Mr Abbott was saying he had made ministers see the errors of their ways.

Another said he was doubtful the warning against leaking would be heeded, saying "history says probably not".

A leak of Cabinet debate last week detailed how six ministers - Julie Bishop, Malcolm Turnbull, George Brandis, Christopher Pyne, Kevin Andrews and Barnaby Joyce - spoke against a proposal to strip citizenship from sole citizens, complete with quotes and their various arguments.

In Parliament, Mr Abbott parried a question from Opposition Leader Bill Shorten on what he did to find the ministers responsible for the extraordinary leak.

"I want to assure the Leader of the Opposition and members opposite and indeed the entire Australian community that this Government has a strong and effective policy to keep our country safe," the PM said.

"That was further strengthened by the decision the Cabinet made last Monday night.

"It was a decision to strip citizenship from terrorists with dual nationality."