Queensland will have to wait months to learn if its 15-year-strong credit rating has been downgraded as politicians point the finger over spending.
S&P Global Ratings confirmed Queensland's AA+ credit rating - which it has held since 2009 - is at risk if further pressure is applied to the budget.
Treasurer David Janetzki told an Australian British Chamber of Commerce lunch on Wednesday a deep dive into government books could reveal further cost overruns.
The Liberal National Party took power after winning the October 26 election but endorsed the June budget sight unseen.
"We will continue to look under the bonnet and at the various cost overruns that are there," Mr Janetzki told reporters on Wednesday.
"This will be a long process and Labor have left us with an inheritance that they had deceived Queensland about."
Opposition deputy leader and former treasurer Cameron Dick rubbished the accusations, saying the budget and credit rating had been stable under Labor.
"They put us on a stable outlook which means they did not see any danger of a credit downgrade under the Labor government," he told reporters on Wednesday.
"The only thing that's changed since then is a new LNP government that promised $20 billion in election commitments and put forward an absolutely cooked costings document."
Mr Dick conceded a downgraded credit rating could mean higher borrowing costs and result in less infrastructure and fewer services for Queenslanders.
S&P Global Ratings analyst Anthony Walker said cost blowouts and extra spending on new policies could weaken the state's budget and increase debt beyond expectations.
"This could pressure our AA+ credit rating on Queensland, especially if additional spending is not offset by savings or revenue increases," he said.
The ratings agency did not indicate what the credit score could fall to.
The best borrowing rating is AAA, followed by AA+, AA and AA-.
A downgrade in the state's creditworthiness would increase project borrowing costs as Brisbane prepares to host the Olympics in 2032.
Treasury had said in the budget that coal royalties were poised to drop by billions.
Queensland's credit rating is equal second with South Australia, with Western Australia on top at AAA.
NSW, Tasmania and the ACT have an AA+/Negative rating while Victoria is AA/Stable.
Mr Janetzki said S&P Global warned him a continued decline in the state's financial position could result in growing debt.
He has committed to stabilising what he says is an out-of-control financial position and securing the AA+ credit rating,
However, Treasury briefings have revealed that might not be tenable, with Queensland's debt burden growing.
Mr Janetzki has blamed declining coal royalty income - set to fall from $10 billion in 2023/24 to $6 billion in 2024/25 - a GST shortfall and inherited project cost blowouts for the added pressure on the budget.
He promised a "calm and methodical" approach to the budget to get debt under control without cuts to the public service.
