Labor leader Bill Shorten has defended his plan for major changes to the tax system, which the government says amounts to a $387 billion slug on Australians over a decade.
On the first full day of campaigning ahead of the May 18 election, Treasurer Josh Frydenberg released costings which he said showed Labor wanted to "stifle aspiration" and damage the economy.
Mr Shorten, who campaigned in Sydney, said there were clear economic and social benefits to Labor's plan to overhaul negative gearing and capital gains tax and wind back franking credit refunds.
"What we choose to do is spend scarce and important taxpayer money on educating the kids, on decreasing the out-of-pocket costs of cancer treatment, rather than spend it on tax loopholes ... or property subsidies," he said.
The opposition leader said he expected the government's attacks on Labor to "get louder, shoutier, more aggressive and more exaggerated".
Mr Frydenberg rejected Labor criticism that Treasury did not usually cost opposition policies.
"These are Treasury costings and, as Wayne Swan said when he was treasurer of Australia, Treasury do cost alternative policies and it's important to have an informed debate," he told reporters in Melbourne.
The $387 billion figure over the next decade is almost double what was previously estimated.
It includes Labor's decision not to match the coalition's 2022 and 2024 income tax cuts, as well as the property investment changes and franking credits policy.
Prime Minister Scott Morrison says Labor should reveal how much their plan will cost.
"The real question is why hasn't Bill Shorten told you about how much more his taxes are going to cost you?" he asked reporters in Sydney.
Mr Shorten visited a flower market in the seat of Reid before making a $125 million cancer research announcement in the seat of Bennelong.
In 2016 Craig Laundy was the first ever Liberal to win the seat of Reid, with a 4.7 per cent margin, but the close Turnbull ally is retiring and Labor has strong hopes of the electorate returning to the fold.
Liberal John Alexander has held the seat of Bennelong since 2010, holding it by a margin of 4.9 per cent.
But Labor is hoping its high-profile candidate, former Australian Medical Association president Brian Owler, can clinch the seat.
Mr Morrison campaigned in the seat of Lindsay, visiting an oil company in St Marys.
Labor's Emma Husar won the seat from the government in 2016 with a 1.1 per cent margin but she is not recontesting the post after a scandal involving her treatment of staff.
Melissa McIntosh will try to prise it back for the Liberal Party, while Labor is running former NSW state minister Diane Beamer.
The leaders have also agreed to a head-to-head debate in Perth before Australians cast their vote.
