Australians will not pay tax on federal disaster assistance they receive to rebuild from this summer’s bushfire crisis, in a decision that adds to the budget cost one day after the Morrison government unveiled a $2 billion recovery fund.

The tax break will be put to Parliament when it returns on February 4 and appears certain to gain support, with Labor making no criticism of the government for trimming the budget surplus to respond to the destruction.

Prime Minister Scott Morrison visited South Australia's Kangaroo Island, which has been devastated by bushfires. Credit:AAP

Prime Minister Scott Morrison revealed the changes on Wednesday when visiting Kangaroo Island in South Australia, where the Australian Defence Force has been delivering clean water and other supplies after bushfires.

But Mr Morrison remains the subject of political attacks over his handling of the fires, with Opposition Leader Anthony Albanese arguing he should have held a meeting with state leaders in November to prepare for the threat.