The government has manoeuvred itself into a problematic position on national security, propelled by ego and the weakness of Prime Minister Malcolm Turnbull’s position.

From London, the prime minister has again left the door open to a major shake-up of institutional arrangements for Australia’s security agencies, referring positively to the British “integrated Home Office … in which they have all of their domestic security agencies — MI5, police and border protection, immigration — is all part of that.”

“We’re very always interested in learning about the British experience,” Turnbull said.

The British experience is terrorist attack after attack after attack, with police officers saying the slashing of thousands of police numbers by then-home secretary Theresa May directly affected their ability to protect Britons. Every single perpetrator of the UK attacks has been known to British security agencies or police. What exactly you’d learn from the British experience other than “don’t do that” is a mystery for the ages.

Nonetheless, the merger of anything vaguely security-related into a mega-portfolio with the name “home” shoehorned into the title is the unkillable zombie of reshuffle ideas in Canberra. Not even the serial, and spectacular, incompetence of the Department of Immigration and Border Protection under Peter Dutton and Secretary Mike Pezzullo has been enough to fell the idea; putting the people who oversaw the billion-dollar offshore processing tender debacles, the deaths, rapes and assaults of detainees, the detention of Australian citizens, the failure to properly monitor visa compliance, lack of proper checks on citizenship applications, farces like Operation Fortitude, the inability to protect their IT systems and inability to sort out their own accommodation, in charge of protecting Australia is profoundly worrying.

There is a deeply embedded culture of non-accountability and basic incompetence in the Immigration portfolio that should be a huge red flashing light against incorporation of national security functions.

Nonetheless, Peter Dutton, the most prominent right-winger in the government, wants to expand his power; already he exercises a veto over budget measures, to the chagrin of Treasurer Scott Morrison, but he wants to be homeland/office security tsar as well. And because Turnbull is in such a weak position, what Dutton wants, Dutton may well get. It’s national security policy by ego and political weakness.

That’s the first area in which Turnbull’s weakness may well dictate his approach to national security. In another area, it has already happened. Since becoming prime minister, Turnbull has appointed three hard-right figures to chair the Joint Parliamentary Committee on Intelligence and Security: the unlamented political failure Andrew Nikolic, then Michael Sukkar and, after his promotion, Andrew Hastie.

Hastie is described in some media reports as a “rising star” but his performance as chair of what should be parliament’s most important committee is less than stellar: the committee appears nearly moribund. It currently has just three current inquiries, two of which date from 2016, and for which submissions closed nine months ago; one of those, in any event, is a pro forma inquiry into the budgets of intelligence agencies. The contrast with the committee under Dan Tehan’s chairmanship, in the Abbott years, is remarkable.

The problem with appointing any “rising star” to chair the committee is that they place their ambitions ahead of making the committee what it should be — a rigorous and non-partisan mechanism for scrutinising security agencies, to the discomfort of the latter, ideally. Hastie is a newcomer to parliament as well, having been elected less than two years ago, meaning he lacks the experience and knowledge to stand up for the committee within his party and within government.

Turnbull’s latest security fixation, his proposal to make the internet radically less safe by breaking encryption, would be an ideal subject for a JCIS inquiry — although it would become a forum for cybersecurity experts to explain, in pointed detail, how terrorists, organised crime, enemy states and malicious online actors would benefit from it. And deputy chair Anthony Byrne’s proposal for an investigation of foreign government influence of political parties has been brushed aside.

The government would insist, naturally, that all of this is subject to the conclusions of the current review of the intelligence community by Michael L’Estrange and Stephen Merchant — including “the effectiveness of current oversight and evaluation arrangements”. Australia badly lags both the UK and the United States in parliamentary oversight of our security agencies, which have grown massively in terms of both power and resourcing over the course of the failed War on Terror without effective, independent parliamentary oversight.

Theoretically, moving security and intelligence functions into a homeland security-style body would increase parliamentary accountability given it would function more like a normal department for the purposes of parliamentary committee hearings. But does anyone seriously think a government that devised the furphy of “on-water matters” would allow that?