ACT Chief Minister Andrew Barr says the onus is on the private sector to achieve the territory's ambitious infrastructure goals over the next three years.
Ratings agency Standard & Poor's said it expected the government would only be able to deliver about 80 per cent of its planned multi-billion infrastructure program.
Part of the reason was the existing "capacity constraints" in the engineering and construction sector.
Major government infrastructure projects - like the $500 million Canberra Hospital expansion - have faced years of delays before even going out to tender.
But Mr Barr said the ACT's ability to achieve its infrastructure goals was largely in the hands of the private sector.
"The government does not undertake the work itself, it puts it out to the market," he said.
"One of the risks in a pandemic is that there may be some supply side constraints.
"This plan is at the upper end of our industry capacity, but the MBA and many others have time and time again called for a pipeline and for the government to have more projects available.
"It's now over to the membership of the MBA and others to deliver the projects."
Asked whether it was fair to put all the onus on the private sector when the government had fallen years behind in planning for projects like SPIRE, he said the delays were necessary to properly plan the expansion.
Clinicians and community groups have criticised the lack of consultation for the hospital expansion, especially in the years leading up to 2019.
"If we don't respond to feedback that is apparently not proper consultation, and when we do and change things, and that means there is a delay in the timeframe of the project, then we are criticised for not delivering things quick enough," Mr Barr said.
Liberal leader Alistair Coe described the ratings agency's assessment of the Barr government's capacity to deliver its promised infrastructure blitz as "pretty significant and pretty damning".
"The Labor-Greens government has very poor form when it comes to delivering on their commitments and promises," Mr Coe said.
"You only need to look at the hospital expansion, promised over a decade ago and promised every year or two since. It shouldn't be that way."
Mr Coe was coy on which of the planned projects would be delivered, or scrapped, under a Liberal government. He said the Liberals would set out its infrastructure agenda in the coming days and weeks.
Master Builders ACT chief executive Michael Hopkins said it would require collaboration between government and industry to achieve the infrastructure goal.
"Industry certainly has spare capacity to deliver an increased capital works program," he said.
"But we cant deliver those programs unless government has completed design approval and put those projects to market for tender.
"We're confident that once the government works through its complicated procurement system there will be a strong appetite from local contractors to deliver infrastructure projects."