Chief Minister Andrew Barr says he will seek urgent advice on whether the National Capital Authority's delayed works to strengthen the Commonwealth Avenue bridge would push out the completion of light rail to Woden.
Mr Barr did not rule out the authority's delay would hamper construction of light rail across the lake, but said he had no advice to say it would.
"I have no advice that it would change our time frames but I need to have that confirmed," Mr Barr said.
The authority's annual report confirmed the $137.5 million project to strengthen the bridge had been delayed. The works need to be completed before a new bridge can be built between the existing spans to carry light rail tracks across Lake Burley Griffin.
Mr Barr was elected chief minister in a ceremonial sitting of the Legislative Assembly on Wednesday morning, after securing confidence and supply agreements with the ACT Greens and independent Thomas Emerson.
Talks between Labor and the Greens on the Greens entering another coalition partnership broke down on Tuesday evening. The Greens will sit on the crossbench.
Greens leader Shane Rattenbury said Labor had been unable to commit to policies that included speeding up light rail.
"They were not prepared to build a single house beyond their current policy, they were not prepared to properly invest in walking and cycling infrastructure and seek to accelerate light rail," Mr Rattenbury said.
"Everybody else in Canberra knows you can do it faster, but the Labor Party are stuck where they are on their approach. That is not a position we could sign up to."
Mr Barr said the Greens' time frame to bring forward the construction of light rail was simply not practical or feasible.
"And I need to only point to a very timely article on the front page of The Canberra Times last weekend around the delays of the National Capital Authority's works on the bridge," he said.
"That certainly sent a pretty clear signal that that project has a number of external factors that impact on its timing."
Mr Barr said he knew some people wanted light rail to be built faster, but said the project was big, complex and expensive, and the government was particularly focused on developments around three new stops to be built as part of stage 2A.
"We will be extending the line in this next term and we will get on with the work that's necessary to get stage 2B to an investment decision point," he said.
Construction on the extension to Commonwealth Park will start in late 2024 and is expected to take about three years. That means the 1.7-kilometre line will open in January 2028, more than 8.5 years after the first stage opened between Gungahlin and the city.
Mr Barr said before the election he was open to considering opening the Woden light rail extension in sections in an effort to get people moving to the parliamentary triangle faster.
A construction contract for stage 2B of the light rail project is not due to be signed until after the 2028 election.
Work on the final concept design and environmental approvals is expected to continue until mid-next year, before detailed design and planning approvals are completed between mid-2025 and mid-2028.
Between mid-2027 and mid-2029, the stage 2B business case would be finished and considered, main works procurement would take place and a contract awarded.
Mr Barr in March said the government was working towards a construction period of 2028 to 2033 for the Woden light rail project.
