Treasurer Ben Wyatt is set to defy the global economic downturn with a healthy set of numbers when he hands down the budget on Thursday.

A resurgent iron ore price has effectively ensured the finances will be kept in the black despite the $5.5 billion cost of the McGowan government's COVID-19 state recovery plan.

Massive infrastructure spending is expected in a budget that will also look to consolidate Labor's pole position ahead of the state election next March.

"You can expect a stronger state and a safer state," Premier Mark McGowan said on Wednesday.

"That is our focus - keep people healthy and make sure we create jobs.

"We have been the government with the best financial management in Australia for the last three years and you'll see that continue."

The premier refused to confirm whether the budget would predict surpluses throughout the forward estimates.

But he rejected criticism from the state and federal Liberals that the government should be spending more rather than banking a surplus.

"The state government, like all governments, needs to have the capacity to respond if a second wave of coronavirus comes along or if there's a further economic problem," he said.

"The idea that somehow bankrupting the state is a good thing is wrong. You've got to actually have capacity to deal with problems as they arrive."

Whatever surplus is forecast for 2020/21, it won't be on the scale of the $2.6 billion that was projected for last financial year.

That figure has already been reduced to $1.7 billion in last month's annual report on state finances, which highlighted a fall in most revenue sources.

The unexpected strength of the iron ore price, which remains around $US120 per tonne, has helped significantly to counter that decline.

The state government also credits its decision to prioritise removing restrictions within WA ahead of reopening state borders for cushioning the economic blow.

But the government's efforts to pay down debt are set to take a hit with borrowings set to increase.

Every WA household will receive a $600 credit towards their electricity bills, which is expected to cover average power costs for about four months.

The one-off credit, to be received from November 1, is being funded out of the recent Bell Group settlement, which returned about $665 million to WA taxpayers after costs.

The government anticipates about 70 per cent of the money will be spent and 30 per cent saved.

Further sweeteners are likely as polls show the WA Liberals are facing another bruising defeat at the March state election.

Taxpayers have already benefited from a freeze on electricity and water tariffs, motor vehicle-related charges and public transport charges.

The average WA household can also expect a one-off reduction of about 10 per cent on household fees and charges this year.

Australian Associated Press