The Prime Minister insists the Coalition's approach to Australians fighting for Islamic State, or Daesh, is now crystal clear. "If you are just an Australian citizen and you are a terrorist and you come back to Australia, we will lock you up; if you are a dual citizen and you leave Australia to fight for a terrorist army … we will strip you of your citizenship because we never, ever want you back." Here, writ large, is Abbott's view that such people are not deserving of the benefit of the doubt. Next week we will see the legislation that will give Immigration Minister Peter Dutton the discretion to implement the policy when it comes to dual nationals. In contrast, Abbott asserts Labor's approach is to "welcome" alleged terrorists with dual citizenship on their return and "no doubt roll out the red carpet for them like it rolled out the red carpet for people smugglers when it was in government". Why? Because shadow Attorney-General Mark Dreyfus gave a straight answer when asked on Sky News on Thursday how an Australian fighting in Syria could be convicted of a terrorism offence. "You get them back here," he replied. The same day, the Australian Federal Police offered an example of how this would work, issuing an arrest warrant for Tareq Kamleh, the Australian doctor who has joined the Islamic State and appeared in a recruitment video for the terror group.

The warrant relates to three offences: being a member of a terrorist organisation, recruiting for a terrorist organisation, and entering a so-called "declared area" or terrorism no-go zone under laws passed by the Abbott government late last year with opposition support. "Should Dr Kamleh return to Australia, this warrant authorises law enforcement to arrest him immediately," the AFP said. Hardly a red carpet. Deliberately, Abbott is escalating the politics of national security at the very time when Shorten is under the greatest pressure, and most intense scrutiny, of his 20 months as Labor leader. How Shorten responds will be either the making or breaking of him. In his determination to project strong, uncompromising leadership on national security, Abbott has also been willing to misrepresent the position of Bret Walker SC, the former Independent National Security Legislation Monitor. Last year, Walker proposed that the government consider giving the immigration minister the power to strip dual nationals of their Australian citizenship where "it is in Australia's national security or counter-terrorism interests". Even after Walker clarified that this recommendation had been made in the context of existing powers requiring a person be convicted before citizenship can be taken away, Abbott continued to verbal him, telling Parliament: "Obviously he has changed his mind".

Walker's disgust is palpable. "This is point-scoring of a kind I have not experienced since I left primary school. It's childish," he tells me. "They still haven't explained why any country would want to punish people for criminal offences without giving them a fair trial. They still haven't explained how the punishment of people without process of law isn't rather the action of IS than of a country like Australia. And they still haven't explained why, if they think this is a good idea, it doesn't apply to a whole range of offences. "None of that has been explained so, by elimination, it is very clear that this is in the nature of wedge - and it shouldn't be supposed it's just a wedge against the Labor Party. It's almost certainly a wedge against the liberal elements in the Liberal Party." Walker concedes that Abbott's approach may appeal to "an instinctive reflex of disgust against these people", but he says it shows "an extraordinarily unprincipled, superficial and thoughtless approach to a problem we have agreed internationally to deal with co-operatively". "The problem is that we are internationally obliged to co-operate with the suppression of terrorism and to do that by having criminal law which provides for appropriate prosecutions of alleged terrorists. You can't do that by refusing to have them back."

Abbott argued on Friday that one reason for not having these people back is that they might be acquitted in the courts, but his national security statement in February provided an answer to this eventuality. "We will ensure returning foreign fighters are prosecuted or closely monitored using strengthened control orders," he said. Aside from how the proposal sits with this country's international obligations is the question of whether it is consistent with the High Court's unflinching view that, in entrusting the courts with deciding criminal guilt and punishment, "the Constitution's concern is with substance and not mere form". Given the opposition to his initial proposals, which including stripping sole nationals of their citizenship when they could claim citizenship elsewhere, Abbott would have been wise to take the legislation back to the full cabinet before presenting it to his MPs next week. He eschewed this path, but has allowed one of the government's more articulate defenders of the rule of law, Malcolm Turnbull, to be involved in the formulation of the legislation. This is some guarantee that what will emerge will survive legal challenge. However, even if the final result stands up as an appropriate response to the behaviour of those who leave this country to join Islamic State, the risk is that Abbott's overt politicising of national security has eroded public confidence and invited cynicism on the issue that, more than any other, should be above politics.

Yes, there may be a short-term, or even a medium-term, political dividend, but it's a hell of a way to run a country. Michael Gordon is political editor of The Age.