The Federal Government has accused the Opposition of playing politics with a national tragedy over questions in Parliament about how the Government handled letters from Lindt cafe siege gunman Man Haron Monis.

Less than three months before the Sydney siege, Monis wrote directly to Attorney-General George Brandis, asking whether it was illegal to contact the leader of Islamic State.

The Attorney-General's department sent a response to Monis suggesting he consider seeking professional legal advice about his inquiry.

The Prime Minister has previously said that he thinks Monis was given "the benefit of the doubt" by authorities.

In Question Time on Thursday, shadow attorney-general Mark Dreyfus asked Foreign Minister Julie Bishop, who represents the Attorney-General in the House of Representatives, what protocols had been changed within the Government after Australia's terror alert was raised to "high" last September.

In response, Ms Bishop accused Labor of trying to politicise a national tragedy.

"Madam Speaker, I have to say that this line of questioning from this former attorney-general is loathsome," she told Parliament.

Undeterred, Mr Dreyfus asked why a letter, sent nine weeks before the siege and referring to the "caliph", did not automatically raise red flags.

Ms Bishop replied that the director-general of ASIO had deemed the Government's response appropriate, and attacked Mr Dreyfus's questioning.

"I find it extraordinary that this former attorney-general is trying to make political mileage out of this national tragedy," she said.

"Madam Speaker, this line of questioning is utterly contemptible and as a former attorney-general he ought be ashamed of himself."

Ms Bishop then further personalised her attack on Mr Dreyfus.

"It's quite evident that titles can be misleading," she told Parliament, "[given] the member for Isaacs [Mr Dreyfus] is referred to as 'the honourable'."

Nikolic ejected from Question Time

Liberal MP Andrew Nikolic was kicked out of Question Time for yelling during Mr Dreyfus's questioning.

He said the sustained attack on the Attorney-General was an example of rampant hypocrisy from the Opposition.

Monis sent letters to former prime minister Julia Gillard and her attorney-generals.

"It really does make a mockery of bipartisanship when you have Bill Shorten agreeing [to] a strategy in Parliament where we have those sorts of questions which try and leverage what was an awful moment in Australian history to try and score cheap political points," Mr Nikolic said.

After Question Time, Mr Dreyfus defended his hard-line of questioning and renewed his demands to know what policies and procedures had changed since the incident.

He said letters received by the Labor government from the Lindt cafe gunman were sent "in a different time" — before the national terror threat level was raised to "high".

"It's one thing to call, as the Prime Minister did on the September 12 last year, for all Australians to be more alert, for all Australians to report anything suspicious to the appropriate authorities," Mr Dreyfus said.

"We're asking, what did the Government do that's changed?"

Dreyfus ignored fact letters sent to previous government: Brandis

In a statement, Senator Brandis also accused Mr Dreyfus of hypocrisy.

"Mark Dreyfus's attack on me, based on a letter sent by Man Haron Monis and replied to by the Attorney-General's Department, ignores the fact that the matter was dealt with in exactly the same way as it would have been under previous attorneys-general, including Mr Dreyfus himself," Senator Brandis said.

"Mr Dreyfus also avoids the fact that letters from Monis were sent to him, as well as to other Labor ministers, including prime minister Gillard and attorney-general McClelland."

Labor's repeated questioning of the Government's handling of a national security matter during Question Time is a marked departure from its recent bipartisan approach on terror-related issues.

Mr Shorten has regularly told Parliament that Labor stands "shoulder to shoulder" with the Government on the issue.