The opposition leader says the Labor government is failing to keep spending under control as cost of living pressures weigh on Australian households.
Peter Dutton says the government has not cut spending on consultants and other key areas it promised to trim at the federal election.
"It promised to cut spending by $3.6 billion on consultants and contractors and by reducing departments' budgets on advertising, lawyers and travel expenses," he said at a business conference on Wednesday.
"Instead, it's already spent $1.2 billion this financial year alone and locked in $2.5 billion in ongoing contracts."
He also said the government had abandoned the tax-to-GDP cap of 23.9 per cent and had no plan to keep taxes low.
"They're reckless with spending, they're careless with cutting and undisciplined in saving," he said.
Treasurer Jim Chalmers, due to hand down his second budget in May, said there was a need to show restraint in the budget to assist the Reserve Bank in its fight against inflation.
"We will do that in every budget. We will look for areas where we can trim spending," he told ABC Radio on Wednesday.
"Restraint's important but in addition to the magnitude of the spending, which does matter in times like these, also the quality of the spending matters."
He said spending on cheaper education and lowering energy bills, for example, would address, not exacerbate, the inflation problem.
The treasurer also said the government found more than $20 billion in savings in the October budget and banked 99 per cent of the upward revisions to revenues due to high commodity prices.
Mr Dutton accused the government of experimenting with a "system of socialism" that has "devastated nations wherever and whenever it's been implemented".
"Without an economic plan, and with only an ideological agenda, the government is steering a nation towards a dark place in 2023," he said.
Dr Chalmers said Mr Dutton's suggestion his government was experimenting with socialism was a scare campaign.
"These ridiculous scare campaigns and this kind of hyperventilating hyperbole every day just reminds people that he's learned nothing from the last wasted decade of needless conflict," he said.
