Prime Minister Malcolm Turnbull has not repeated a senior colleague's call for Labor to dump its candidate for the Melbourne seat of Dunkley after it was revealed she campaigned against tougher national security laws.

However, Mr Turnbull said the revelation would be a test for Opposition Leader Bill Shorten.

In 2009 Peta Murphy was among a group of lawyers who made a submission to parliament urging the Government to deny police and the domestic spy agency ASIO stronger powers to detain terror suspects without charge.

Attorney General George Brandis said he was "very alarmed" at Ms Murphy's stance and demanded Mr Shorten immediately dump her as Labor's candidate.

"That submission was made a matter of weeks after it was disclosed that the Al-Shabaab terrorist group had been engaged in a plan to attack the Holsworthy Barracks in Sydney," he told reporters.

"It is shocking that the Labor candidate … should be a person who, within weeks of people being charged for an attempted terrorist strike against an Australian military base, should be calling into question both whether or not Al-Shabaab should be listed as a terrorist organisation, which she did, and whether we should have specific anti-terrorism laws, which she also did."

Loading

Mr Shorten rejected Senator Brandis's call and reminded him the former human rights commissioner-turned Liberal candidate for Goldstein, Tim Wilson criticised elements of the Government's counter-terrorism laws last year.

Mr Turnbull has previously urged caution on counter-terrorism laws, telling the Sydney Institute last year it was important that measures were right and effective, rather than simply being tough.

During that speech, he also warned against overestimating the threat posed by Islamic State threat and amplifying its significance.

When asked about Senator Brandis' comments, Mr Turnbull said it was a matter for Mr Shorten.

"The attorney general has called on him [Mr Shorten] to dis- endorsed the candidate," he said.

"It is a matter for him to make his decision on that matter."

Mr Turnbull said the Coalition had no tolerance for terrorism and, in a pointed message to Labor, said any party seeking to form Government should take exactly the same approach.

The Coalition is fighting to hold onto the Victorian seat of Dunkley following the retirement of popular Liberal MP Bruce Billson.