It's the first time the fund has been used to respond to a natural disaster since it was established three years ago. The government has been under increasing criticism from Labor to use the pool of money, rather than just allowing it to accumulate $800m in interest.

The $4.8b ERF was established in 2019, and allows for up to $150m a year to be spent on emergency response and recovery, and $50m a year on disaster mitigation. However, only $100m has been offered up to fund two rounds of flood mitigation projects, none of which have started construction.

Emergency Management Minister Bridget McKenzie said the Queensland and NSW governments would each receive a grant of $75m to spend where they determine it is most needed.

"Due to the significant devastation wreaked by these floods, we are allocating the total $150 million available from the Emergency Response Fund this financial year to this effort," Senator McKenzie said.

"The scale and magnitude of these floods is exactly the type of event that the Emergency Response Fund was designed to address."

IN OTHER NEWS:

Labor emergency response spokesperson Murray Watt said the funding was "too little, too late" and the government was only dipping into the ERF because there was an imminent election.

"In three years, it has not spent a cent on disaster recovery or even started building a single disaster mitigation project," Mr Watt said.

"This fund could have built flood levees, drainage improvements, cyclone shelters and bushfire evacuation centres to keep Australians safe.

"Tragically, it's Australians who've paid the price for [Prime Minister] Scott Morrison's incompetence, through floods, cyclones and bushfires."

Labor has promised to revamp the ERF if elected and spend up to $200m on disaster readiness.

Senator McKenzie said so far the federal government had already committed more than $923m in direct payments to support flood victims, along with $1.5 billion towards the joint Commonwealth-State Disaster Recovery Funding Arrangements.