Daniel McCulloch and Rebecca Gredley
(Australian Associated Press)

Scott Morrison is promising a national inquiry into the bushfire crisis will be “very swift”.

“This will be done by the end of August,” the prime minister said on Tuesday.

The inquiry will first look at all previous royal commissions into bushfires across the country and audit the various recommendations.

“There’s already been a lot of work done on that so they’ll be able to move on that very quickly,” Mr Morrison said.

“The second thing it will be doing is looking in a very focused way at how, and on what trigger, the federal government can actually on its own initiative put its own personnel, defence force and others, and get them in there on the ground.

“We need to know better at what point we can do that in the future.”

The inquiry will also look at issues including hazard reduction burns, land clearing and native vegetation laws.

“Practical things so we can get ready for the next season,” the prime minister said.

Draft legislation to exempt bushfire relief payments and volunteer loss-of-income grants from tax has passed the first hurdle of parliament on Wednesday, with the government hoping to have it rubber-stamped quickly.

State premiers are weighing up the prime minister’s proposal for a royal commission into this season’s deadly bushfires.

Mr Morrison has written to all state and territory leaders seeking their feedback and approval for a probe into the fires, which have killed more than 30 people.

Mr Morrison wants former Australian Defence Force chief Mark Binskin to lead the royal commission, which he hopes will “make our country safer and our communities more resilient”.

Victorian Premier Daniel Andrews has previously questioned what a federal inquiry would achieve, as a $2.55 million inquiry has been launched to review the state’s bushfires.

Mr Andrews’ office said they had received the prime minister’s letter.

“We are considering the Commonwealth’s request,” a spokesman told AAP.

Independent inquiries have also been launched by the South Australian and New South Wales governments into the bushfires.

Tuesday was the first day of parliament for the year and was entirely dedicated to the bushfire tragedy, with MPs paying tribute to victims of the ongoing crisis.

Firefighters will be posthumously eligible for a national medal, Mr Morrison announced.

Climate change’s role in making Australia’s bushfire season longer and more severe was raised by multiple MPs, with the government urged to do more.

Meanwhile, hundreds of protesters rallied outside Parliament House calling for greater action on climate change, as part of a People’s Climate Assembly.