Scott Morrison says lower-paid workers will be better off under his tax plan, as he continues to attack Labor's handling of the economy.
Bill Shorten is promising to make sure cancer patients and older Australians don't get stung with fees for pathology if bulk-billing ends.
The prime minister will start the day in Melbourne on Tuesday, while Mr Shorten is expected to fly to Adelaide to campaign.
The coalition argues teachers, nurses, police officers and tradies stand to pay hundreds of dollars more in income tax in 2024/25 under Labor.
"Anyone earning more than $40,000 will better off under our plan," Treasurer Josh Frydenberg said.
"It means school teachers, nurses, bus drivers and emergency service workers right across the country will have more money in their pocket."
Labor does not support stages two and three of the coalition's tax cuts, but Mr Shorten has promised to look at tax relief if the budget can handle it.
Mr Shorten is promising $200 million to ensure pathology clinics keep bulk billing, as he says the system is in a crisis.
The Medicare rebate for pathology has been frozen since 2003, but Labor and coalition governments have offered incentive payments to bulk bill since then.
But the industry says the top-up payments can no longer cover the costs.
"Bulk billing for blood tests is at breaking point - cancer patients will either have to pay, or there will be a reduction in services," Mr Shorten said.
"That's why Labor will invest $200 million to protect pathology and keep it free for vulnerable Australians.
"We will work with the sector and lift the bulk billing incentive - the payment which keeps these services free - to save bulk billing for cancer patients and older Australians."
Australian Pathology chief executive Leisel Wett said if people avoid tests due to the cost, diseases will get diagnosed later and at greater cost to the taxpayer.
"Without adequate funding, pathology services will be forced to stop bulk billing," she said.
The funding promise is part of Labor's $2.3 billion injection into healthcare, which the party is relying on to help win votes.
Mr Shorten is expected to campaign in Adelaide on Tuesday, after spending Monday in the Liberal-held seat of La Trobe in Victoria.
Mr Morrison campaigned in Deakin on Monday, announcing road funding in a bid to shore up Liberal MP Michael Sukkar's 6.4 per cent margin.
Australian Associated Press