CANBERRA, AAP – Deputy Prime Minister Barnaby Joyce says it is vital not to lose sight of how to pay for health and welfare as voters head to the polls on May 21.

The incoming federal government will have a role in assessing at least three coal mines in Queensland.

Renewable energy and phasing out fossil fuels are key issues in many seats, with a new wave of independents campaigning against coalition MPs arguing for stronger action on carbon emissions cuts.

The Greens are also aiming to pick up a number of new Senate seats by campaigning on more ambitious climate action.

Throwing his support behind more coal development, Mr Joyce said a coalition government would invest in “the things that make us money”.

“Medicare and social security have to be paid for,” he told the Seven Network on Monday.

“We are the side that is brave enough to say that we make it from iron and coal and gas, and if we lose sight of that we’re not making the money that can support all of the vital economic and social infrastructure so important to this nation.”

Labor frontbencher Tanya Plibersek said her party would welcome a debate on economic management.

“This is a government that actually doubled the debt before COVID-19 hit,” she said.

“The Morrison government and the Howard government are the two highest taxing governments in the last 30 years.”

She said the Morrison government had admitted low wages were a deliberate design feature of its economic management.

“We want to lift that (cost of living) burden to make sure that they have good jobs and a pay rise and cheaper childcare and cheaper healthcare and an easier life.”

The Pre-Election Economic and Fiscal Outlook, which provides independent updated information on the economy and budget ahead of the election, is due to be released this week.