The most important duty of a government is to keep its people safe.

That’s why Labor has worked sensibly and co-operatively with the government on national security, and will continue to do so.

We have provided bipartisan support for Australia’s intervention in Iraq against the evil Daesh (Islamic State) – an organisation that is murdering, raping and enslaving men, women and children, and urging attacks in Australia.

Labor arrived at this position after a great deal of careful thought. We took extensive advice, we balanced the evidence, we drew on the lessons of the past and we considered our capacity and responsibility as a nation to respond.

Australia has a responsibility, working alongside the international community, to protect vulnerable civilians from mass atrocity crimes. The invitation of the Iraqi government gave us a sound legal basis for entering Iraq to do so.

A couple of days ago, the government, with Liberal backbencher Dan Tehan as its frontman, used the media to float the idea of extending Australia’s military involvement into Syria.

Yet again the Australian people learned about a national security matter from a newspaper rather than from the prime minister.

To send our servicemen and women to one of the most dangerous places on Earth is an extremely serious decision and it should not be taken lightly.

As the prime minister has acknowledged himself, many times, the legal basis for Australian intervention in Syria is unclear.

If the prime minister’s view has changed he needs to explain to the Australian people why.

There are many serious questions that remain unanswered.

What would Australia’s strategic objectives be, and what has changed to necessitate our involvement? What would our role be – air strikes only, troops on the ground, or something else? What would success look like? Is this the best way Australia can help solve the crisis in Syria? Is there a sound legal basis for Australian involvement in Syria?

And what additional support are other countries, especially those in the region, expected to provide? Australia is already one of the biggest per capita contributors of troops to the mission in Iraq. Australia has sent one soldier for each 24,000 of our citizens.

There is no doubt the humanitarian situation as a result of the conflict in Syria is unprecedented. Around 11.5 million people, just under half the Syrian population, have been forced to flee their homes – including millions of women and children. Australia can, and should, be doing more to help these victims of Daesh in Syria and in neighbouring countries such as Turkey, Lebanon and Jordan.

The government has been quick to raise the prospect of bombing in Syria, but slow to respond to the humanitarian crisis.

Daesh is a shockingly brutal force that is destroying the lives of many innocent people. If the government has a case to make about a potential change to Australia’s existing mission in Iraq, we are ready to hear it.

We agree decisions about Australia’s national security should be above politics. But they should not be beyond scrutiny. And they should not be beyond question.