The Greens have condemned a budget plan to lift 80,000 Australians out of poverty with a cost-of-living package as a betrayal at the same time as they push for extending childcare subsidies to families earning over $530,000 a year.

Greens leader Adam Bandt condemned this week’s budget as a “betrayal” of “everyone doing it tough” on Wednesday morning.

Mr Bandt blasted the modest increase to welfare payments and a mix of one-off cost-of-living measures even as expert analysis shows they would move 80,000 Australians out of poverty.

TND understands negotiations over the budget with the Greens will begin this week with a proposal to amend the budget to include a policy to make child care free for all families.

Under recently passed legislation, the government pays some childcare subsidy to families on incomes of up to $530,000 a year.

It is not known how much the Greens proposal to remove that cap would cost the taxpayers.

But a spokesman for the Greens leader denied the party was going to stand in the way of the package after he had earlier described the measures as a betrayal of those on the JobSeeker income-support payment.

“It’s clear that Labor’s budget has only tinkered around the edges instead of addressing the magnitude of the poverty and housing crises,” said Senator Janet Rice, poverty spokeswoman for the Greens.

About 750,000 Australian children live in poverty, a University of NSW analysis published in October showed.

“I’m happy for every person who gets out of poverty but it will take – and we have – a lot more,” said Greens Senator and economics professor Barbara Pocock, while declining to discuss negotiations.

Budget’s Twitter critics

But on budget night Twitter critics rounded on the government’s $2 billion poverty alleviation package and sent the #JobSeeker trending.

On Wednesday, new research from Australia’s most respected researcher of income inequality, Ben Phillips from the ANU Centre for Social Research and Methods, found its effect on lifting families out of poverty would be very small but measurable.

After a last-minute windfall left the budget flush with over $100 billion in revenue from sky-high resources prices and near-record-low unemployment, Labor is proposing some additional cost-of-living measures for families on income-support payments.

Adding together the payments, from energy rebates to Medicare bulk billing appointments, Associate Professor Phillips’ calculations showed the effect would be “lifting 80,000 people out of poverty”.

That amounted to about 0.3 per cent of the national population, the modelling found.

TND has requested official data on how many Australians have been lifted out of poverty by federal government programs over the past three decades when there has been no substantial increase to welfare payments.

Associate Professor Philips, who led the expert committee that first proposed the $260 increase that the government turned down, said the budget package, even if passed, would still leave substantial work left to do to end poverty, but said the plan was a significant moment in recent Australian politics.

“When you look at the budget, it is evident that making significant inroads to poverty is not cheap,” he said.

“This budget makes a useful start, and probably [is] the best seen in many years.”

Another proposal to be offered in negotiations, a Greens source added, would be doubling the length of federal-funded maternity leave.

The Labor government passed a 26-week package last year after winning power.

That came nearly 10 years after the same package, then a signature policy proposal of Tony Abbott’s, was sunk by Liberal Party factional bosses.