Major parties have attacked each other on economic management after the NSW budget office put price tags on election promises.

Treasurer Matt Kean labelled Labor’s figures a fantasy, while his counterpart Daniel Mookhey said the Parliamentary Budget Office update showed the coalition had not put aside a single dollar for $53 billion in infrastructure spending. 

The incoming government would face decreased royalties from mining, specifically coal, and a projected reduction in NSW Generation Fund returns as they seek to deliver on election commitments.

The coalition is estimated to deliver a $100 million surplus over the next four years while Labor would add $1.4b, according to the budget office.

Mr Kean said Labor was risking the budget outlook by promising public sector pay rises.

“It is not possible to give public sector workers a pay rise without it impacting the budget bottom line – the numbers simply don’t add up,” he said on Monday.

“Public sector wages account for around 40 per cent of the total NSW budget and the PBO is warning Labor’s wages policy risks the budget outlook at a time when we’re facing economic headwinds.”

The budget office said the fiscal planning environment in which the 2023 election costings have been prepared is more uncertain and volatile than it has been in the two previous elections.

Supply chain uncertainties, the economic impact of Russia’s invasion of Ukraine and unexpected extreme weather events such as floods have contributed to the volatility and uncertainty.

Mr Mookhey pointed to $3b in savings in Labor’s budget to fund public sector wage increases, saying there were “strict budget rules” in place for how Labor would lift pay and conditions.

“If we’re elected this Saturday, we look forward to sitting down with essential workers from Monday onwards,” Mr Mookhey said.

He questioned the coalition’s allocation of $240m for completing metro projects in western Sydney, which he said would cost as much as $20b.

Premier Dominic Perrottet campaigned in Nowra with Liberals candidate Melanie Gibbons, close to bordering Kiama on the state’s South Coast. 

Mr Perrottet spoke to locals about the cost of living, hoping it will give Ms Gibbons an edge against popular local MP Gareth Ward in the seat.

Mr Ward was dumped from the Liberal Party and suspended from parliament in 2022 after being charged with sexual and indecent assault. He denies any wrongdoing and the case remains before the courts.

Amid an ongoing tussle over the state’s toll roads, the coalition announced it would raise the speed limit on major Sydney motorway, WestConnex, to 90km/h, saying it would boost productivity by $80m a year. 

Labor continued its attack on privatisation, saying a re-elected coalition would sell assets including Sydney Water, despite Mr Perrottet ruling it out.

Mr Minns said the premier couldn’t be trusted, pointing to a tweet prior to the 2018 election in which he said there were no plans to privatise WestConnex, which was subsequently sold.

“I’ve got a challenge for him. Back Labor’s plan to put Sydney Water into the NSW constitution,” Mr Minns said in the electorate of Oatley in southern Sydney.

Labor’s proposal would ensure any future sales of public assets need to be approved by parliament.

Mr Minns campaigned at Padstow with candidate Ashvini Ambihaipahar, who hopes to win the long-held Liberal seat.

The premier trumpeted the coalition’s $116b infrastructure pipeline over the next four years, boasting it continued “the biggest building program since federation”.

“Saturday’s vote will decide the future of the NSW economy,” Mr Perrottet told reporters.

“You and your family will be worse under Labor because they can’t manage money well … they will come after your budget,” he said.

Pushed on the state’s debt, which is projected to reach $187b, the premier said it would remain “sustainable and affordable”.

By Farid Farid and Duncan Murray in Sydney