The Australian Greens plan to fight the federal government's budget tax cuts all the way to the next election.
Leader Richard Di Natale made the threat after Treasurer Scott Morrison delivered his third budget to parliament on Tuesday.
"This is a tax plan that will turbo charge inequality in Australia," he told reporters in Canberra.
"It's a tax plan that means someone on two hundred thousand gets a tax break ten times someone on 40 thousand."
Senator Di Natale said instead there should have been more money for schools, hospitals, and measures to tackle climate change instead.
"This is the budget that gives the middle finger to anybody that cares about a safe and stable climate in Australia," he added.
The Greens leader challenged Labor to come out against Mr Morrison's "cruel" tax cuts.
"We'll be fighting this all the way to the next election."
The government has announced a three-stage plan to modestly lower taxes over seven years, starting this year with low to medium salary earners.
Most of the reductions will be in the form of offsets and threshold changes to head off bracket creep.
But by 2024/25, 95 per cent of taxpayers will be paying a marginal tax rate of 32.5 per cent or less.
