Bill Shorten insists Labor is offering a genuine solution to repairing the budget but the prime minister says the Labor leader is just proposing taxes on investment.
In a speech to the National Press Club, the opposition leader unveiled savings and extra taxes worth $8.1 billion over four years and $80 billion over a decade, including changes to negative gearing.
Mr Shorten said that after three years, the Liberal government has added $100 billion of debt.
"Australia's hard-won triple-A credit rating is at risk and if triple-A goes to double-A it will be on the heads of Malcolm Turnbull and Scott Morrison," Mr Shorten said.
But Mr Turnbull won't be supporting Labor's new list of proposed budget "savings".
"He is asking us to support things that we have previously opposed and the reason we oppose them is because they are additional taxes on investment," Mr Turnbull told reporters in Sydney.
The prime minister wants Labor to back legislation for a massive $6.5 billion in savings, known as the omnibus bill and made up of a series of measures Labor said it would support during the election campaign.
Mr Morrison said before the election Mr Shorten took savings included in government legislation into his own costings, which he put to the community.
"He shook with the Australian people on a deal to support those savings for the Australian people," Mr Morrison told reporters in Perth.
"Will he now actually vote in accordance with that deal he did with the Australian people?"
The treasurer said Labor would eventually get the opportunity to vote on a tobacco excise tax lift and other revenue measures.
"We have $40 billion just over the forward estimates of measures, both on revenue and on expenditures savings that will improve the budget," Mr Morrison earlier told Perth's 6PR radio.
The $6.5 billion is just the first step.
Earlier this week, Finance Minister Mathias Cormann likened Mr Shorten to a jelly on a plate over his party's stance on the omnibus bill.
"He should step up, otherwise I think Mathias is bang on, it's wibble wobble wibble wobble," Mr Morrison said.
Assistant Minister for Vocational Education Karen Andrews took the theme further, saying Labor is tossing things backwards and forwards.
"In the space of 24 hours we have gone from wibble wobble, wibble wobble to hot potato, hot potato," she told Sky News.
