Labor says its plan to axe cash refunds for some wealthy investors is just part of its effort to roll back tax breaks for the wealthy if it wins the next election.
Opposition Leader Bill Shorten is also targeting negative gearing reforms, a cap on managing tax affairs, discretionary trust reforms and a crackdown on multinational tax avoidance.
"If elected, Labor will have a fairer tax system and we will create incentive in our tax system for businesses to invest in Australian jobs," Mr Shorten told reporters on Tuesday.
But Treasurer Scott Morrison says Labor is coming after everyone's money in a tax grab.
"We already know that they were going to increase taxes on housing, investments, small business, savings, and on your superannuation," he said.
"The latest tax is to steal the tax refund of older Australians, by making them pay tax twice on what their hard-earned savings has been delivering."
Mr Shorten said Labor's plan to wind back Howard-era rules allowing investors to claim tax imputations from dividends could be used to pay for low- and middle-income earners' tax cuts.
The original scheme was introduced under Paul Keating to make sure company profits aren't taxed twice - once with corporate tax and again via personal income tax.
But in 2000 John Howard allowed investors to get a cash refund from the government if their tax imputation was more than the tax they owed.
Labor says eight per cent of taxpayers will be affected by the tax imputation change.
The party also argues 50 per cent of negative gearing benefits go to the top 10 per cent of earners, meaning Labor's changes will mainly affect the wealthiest.
Labor says less than one per cent of taxpayers will be affected by the cap on managing tax affairs, and just two per cent by the discretionary trust reform.