A secret federal government plan to wedge Bill Shorten, portraying him as indecisive on terrorism, has been undermined after an internal briefing paper instructing ministers on how to argue the point politically was leaked to the media.

The embarrassing breakdown of the government's own security suggests ongoing internal divisions and comes amid growing doubts over the future of its bill to hand the immigration minister the power to strip citizenship from dual nationals suspected of supporting terrorism.

It coincided with a heated argument in Parliament culminating in an attempted censure motion by the opposition over claims the Abbott government paid people smugglers to take 65 asylum seekers back to Indonesia.

The government refused to be drawn on that matter, with ministers from the Prime Minister down citing operational secrecy and adherence to the practice of not commenting on intelligence matters.

But some Liberals went further, with Tony Abbott's hand-picked "special envoy for citizenship and community engagement", Philip Ruddock, dismissing the furore over the payment claims as "nothing".

"The amount of money that was allegedly paid is nothing in comparison to the cost of processing the excessive amount of people who came to Australia as a result of people smuggling activity," Mr Ruddock told News Corp.

"Having so many people come to Australia as a result of the hideous people smuggling trade and processing them in Australia cost millions and millions of dollars," he said.

Foreign Minister Julie Bishop shifted the focus back onto Indonesia, using a newspaper interview to ratchet up criticism of that country for not maintaining adequate levels of border security.

Labor has given in-principle support to the idea of cancelling citizenship for dual nationals suspected of backing terror but wants to see the proposed legislation first, and has reserved final judgment regarding the expansion of ministerial power. At least three crossbenchers in the Senate are unlikely to support the move, meaning it is doomed without Labor backing.

The leaked four-page briefing document, which originated from the Prime Minister's own office, is the latest in a stream of damaging leaks from the top levels of the Abbott cabinet.

Insiders say it would have been circulated to a mere handful of ministers, in order to minimise the chances of it becoming public.

The parliamentary briefing paper shows Mr Abbott's controversial proposal relies on the courts being cut out of the process, arguing that limiting citizenship cancellation only to those people already convicted of terrorism-related crimes by courts would render the change "toothless".

"Why should this power be exercised by a minister and not the courts?" the briefing note asks, before explaining that only by controlling the process can the government deliver the strong laws needed.

"A law requiring a terrorist conviction would be toothless," it states.

"The vast majority of the 50-odd Australian dual nationals fighting with terrorist groups in Syria and Iraq would retain their citizenship if a conviction were required.

"In many cases law enforcement agencies will know an Australian has been fighting with terrorist groups but will be unable to present sufficient eligible evidence to secure a conviction.

"Australians expect us to take every reasonable step to deal with those who are a danger to the community. Does Bill Shorten want a toothless law or one that actually protects the community?"

Legal experts have argued the proposal is unconstitutional and that it represents an unwise expansion of executive power into what is normally a judicial function.

On Sunday, Mr Abbott conceded there was a risk the plan could face a High Court challenge but said the government was "as confident as we can be that the legislation we have in mind will minimise constitutional challenge".

With Labor's position uncertain, at least three of the eight crossbenchers expressed grave concerns about the proposals too.

The government would need at least six of the eight crossbenchers, a figure that may already be beyond reach, in the event that Labor joined the Greens to block the expansion of ministerial power

Following the leaking of the question time brief, Liberal Democrat senator David Leyonhjelm accused the government of "trying to wedge Labor on national security from the start".

Though a critic of the ALP for already signing up to some "obnoxious" national security legislation that affected free speech , Senator Leyonhjelm said the government's behaviour had been "shabby" .

"I am certainly not just going to support ministers having the right to strip citizenship," he said.

"There has been no bill to look at, but it sounds to me like I would support Labor's safeguard, which would be to have a judicial appeal."

Independent senators Nick Xenophon and John Madigan also raised serious concerns about the laws.

Family First Senator Bob Day, however, said he was inclined at this stage to back the laws.

The Greens described the proposed law as a "serious mistake".

Coalition strategists remain confident that, eventually, Labor will back the proposed changes despite growing criticism from the opposition in recent days to the measure.

Comment was sought from crossbench senators Zhenya "Dio" Wang, Jacqui Lambie, Glenn Lazarus and Ricky Muir.

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