The Turnbull government is poised to go ahead with the creation of a national security super-department that would bring together ASIO, the Australian Federal Police and Australian Border Force, according to reports.

Immigration Minister Peter Dutton is tipped to head the new super-portfolio, which will be debated by cabinet on Tuesday and would be based on Britain's Home Office.

After months of speculation, Mr Turnbull now backs the plan, Sky News reported. 

But the plan – arguably the biggest shake-up in the structure of Australia's national security apparatus in decades – is likely to be fiercely debated in cabinet. Attorney-General George Brandis, Foreign Minister Julie Bishop, Justice Minister Michael Keenan and Defence Minister Marise Payne are all understood to oppose the idea. Defence Industry Minister Christopher Pyne is understood to lean against the idea. 

Mr Keenan said only on Monday morning during a press conference that "I don't believe any country is as well equipped to deal with the terrorism challenges as Australia".

"Australians should feel confident that the arrangements we have in place at the moment do serve us very well," he said.

Senator Brandis, currently responsible for ASIO, and Mr Keenan, responsible for the AFP, would be the big losers out of the change. The Immigration Department will lose responsibility for border protection and instead concentrate on issues such as integration and citizenship.

Mr Dutton is known to be in favour of the idea and Sky News reported that he had the backing of Treasurer Scott Morrison and Finance Minister Mathias Cormann.

Mr Turnbull is expected to announce the change as he unveils a review of national security arrangements by former Department of Foreign Affairs head Michael L'Estrange.

However that L'Estrange review – part of a routine reassessment of national security arrangements – is understood not to specifically recommend such a super-portfolio.

Mr Turnbull has been dropping strong hints lately that he is inclined to make a significant change, rejecting what he's branded a "set and forget" policy on national security and warning that Australia must keep up with an evolving set of threats from terrorism to foreign political influence.

Security and intelligence agencies themselves are also believed to have concerns about such a change, while some former intelligence heads have publicly said they do not see any need for change.

Opponents argue that national security agencies already share information effectively and there is no need for a super-portfolio. Australia has prevented 12 terrorist attacks, they argue. Britain has suffered considerably more casualties in Islamist terror attacks though it has larger problem with Islamic extremism.