![Attorney-General George Brandis (pictured) and Justice Minister Michael Keenan have revealed the new five-tier terror alert system - not expected, possible, probable, expected or certain. Photo: Daniel Munoz Attorney-General George Brandis (pictured) and Justice Minister Michael Keenan have revealed the new five-tier terror alert system - not expected, possible, probable, expected or certain. Photo: Daniel Munoz](/images/transform/v1/crop/frm/silverstone-feed-data/2451431d-a603-4601-baa5-702e048bee49.jpg/r0_0_727_410_w1200_h678_fmax.jpg)
Australia has a new five-tier terror alert system but the actual threat of an attack on home soil has not changed, the federal government said on Thursday.
Attorney-General George Brandis said changing from the previous four-tier system would "create more nuance in the system, particularly at the upper end" and would make the threat level more "immediately comprehensible" to Australians.
The old categories gave four threat levels – low, medium, high and extreme – but a review this year recommended an additional category be introduced.
The new system has five tiers to indicate an attack is not expected, possible, probable, expected or certain.
In September last year, the government under former prime minister Tony Abbott upgraded the terror threat under the old system to high.
Senator Brandis said the threat level had not changed and under the new system an attack was "probable".
"We are not announcing an elevation in the threat level. It remains as it has been since 14 September last year," Senator Brandis said.
"Under the old system, that was high, which meant a terrorism event was assessed to be likely. Under the new system, it will be described as probable, which is the equivalent.
"We are not raising the level of the threat but we are expressing it in more accessible and more readily comprehensible language."
![The Paris attacks have not changed the terror threat level in Australia.](http://www.smh.com.au/content/dam/images/g/l/4/r/7/c/image.imgtype.articleLeadwide.620x349.png/1448506306726.png)
The Paris attacks have not changed the terror threat level in Australia. Photo: AP
Justice Minister Michael Keenan said the new system would allow Australia's security agencies to be more specific about threats at the higher end of the scale.
"The new system will introduce a statement of public advice which is agreed nationally and will be released by the Australian government which provides more information on what the
threat means, where the threat is from, potential targets and the means by which a terrorist attack might be perpetrated," he said.
In a speech on national security to Parliament this week, Prime Minister Malcolm Turnbull sought to reassure Australians that while a terrorist attack remains likely on home soil, the Paris attacks has not materially changed the threat here.