Businesses with major damage or a significant dip in revenue because of the fires can access up to $50,000 in tax-free, grant funding.

Low-interest 10-year loans of up to $500,000 will be offered for businesses to restore or replace damaged assets and boost cashflow

Prime Minister Scott Morrison said the first step was for businesses to be able to look forward and see a viable future.

"The biggest crisis that those small businesses face right now is their cashflow," he told reporters in Canberra on Monday.

"We need to try and remove every burden from their cashflow so they can get to that first step."

The loans will be available with a repayment holiday of up to two years, with no interest accruing during this period.

The subsequent interest rate would be set at 50 per cent of the 10-year Commonwealth government bond rate - currently around 0.6 per cent.

Tax assistance will also be provided to people and businesses in bushfire-affected areas.

Small business relief is the latest package to be drawn from the government's $2 billion bushfire kitty, with $500 million to be spent this financial year.

The coalition has signalled it is prepared to sacrifice the much-vaunted budget surplus to respond to the catastrophe.

But Treasurer Josh Frydenberg said he was not in a position to confirm a surplus would not be delivered because the full economic impact of the fires was uncertain.

"When you are responsible economic managers, you have the financial flexibility to respond to crisis and economic shocks whenever they may occur," he said.

An overarching figure on the cost of the small business package is uncertain with damage still being assessed in many communities.

Business Council of Australia president Tim Reed said the fires were bad enough to risk the surplus.

"We do believe that these are exceptional circumstances and while we would love to see the budget in surplus, we would not like to see it in surplus at the expense of these local communities," he said.

Labor's small business spokesman Brendan O'Connor urged the government to provide details on which businesses can apply for help.

"Having looked at the government website, I'm yet to see any guidelines, any parameters, any detail, any forms to fill out for small businesses to make applications for grants or loans," he told reporters in Melbourne.

The government is also tipping $76 million into Australia's ailing tourism sector for promotion and events.

Mr Morrison, a former head of Tourism Australia, said the bushfires were the biggest shock to the industry since the collapse of airline Ansett almost 20 years ago.

"This is one of the biggest, if not the biggest - I would say the biggest - challenge the tourism industry has had in living memory," he said.

Australian Associated Press