Parents are set to receive more help with childcare fees three years after the federal government first laid out its plans, provided a new push to convince parliament is successful.
Prime Minister Malcolm Turnbull has labelled the planned changes "a very big social reform" that would let more Australian parents stay in work.
More than 843,000 families have children in some form of child care.
"Those families have told us that these changes will enable them to make easier decisions to go back to work, to work more hours, to work the hours that suit them," Education Minister Simon Birmingham told reporters at a childcare centre in Canberra on Wednesday.
The plan to scrap the existing complex system of payments and establish a single-fee subsidy is unchanged from what the government proposed in May 2015.
But the government has rejigged the welfare cuts it plans to use to inject an extra $1.3 billion into childcare subsidies, in an omnibus bill it hopes will be more palatable to crossbench senators.
If the legislation passes in the first half of the year, the new subsidy will start from July 2, 2018.
It would be means and activity-tested, giving families between 85 per cent and 20 per cent rebate on childcare fees.
One key change is scrapping the existing $7500 cap on rebates for families earning less than $185,000.
Senator Birmingham said that meant an extra 90,000 families would have their fees subsidised for the entire year instead of facing several months of "a horror for budgeting" when their costs suddenly doubled.
Another 40,000 families on high incomes will have that cap lifted to $10,000 a year.
To pay for the changes the government will phase out Family Tax Benefit A end-of-year supplements but increase fortnightly payments by about $20.
"You would think, given that these reforms will benefit lower and lower middle and income families the most ... given the way they are targeted, so equitably, so fairly that the opposition would support it," Mr Turnbull told parliament later on Wednesday.
The response from the opposition is unlikely to give him confidence.
Labor childcare spokeswoman Kate Ellis complained the government had not done anything to fix problems the sector had raised regarding the activity test and uncertainty for indigenous and rural care services.
"To propose changes with such serious flaws once could be forgiven as a mistake, but to do it three times shows the Liberals simply do not care about the most vulnerable children in Australia," she said.
However, key crossbench senator Nick Xenophon said the reworking of the cuts was a step in the right direction and the childcare package was improved.
The Greens will consider an attempt at splitting the childcare package from the omnibus bill, which spokeswoman Sarah Hanson-Young described as a shell game.
"Why should families trust the government that they give two hoots about how they cover their childcare costs when on the other hand they're making cuts to their other family payments," she told reporters in Canberra.
