The Coalition's unexpected election victory means Canberrans probably won't ride light rail to Woden until 2025, Chief Minister Andrew Barr says.
The ACT government is without the $200 million Labor promised towards the project after Saturday's shock loss, money the territory will have to come up with.
But Mr Barr said the project will also likely take longer to get through the federal parliament without Labor in power, which could set it back years.
"I was expecting or hoping this week to be able to sit down with a Labor infrastructure minister and a Labor territories minister and focus on the parliamentary approval process and on delivering their $200 million commitment to the project," Mr Barr said.
"We're not obviously going to be doing that this week now, we don't even know who the territories minister will be, who the minister for cities and infrastructure will be."
While Labor's promised funding would not have come through until 2021-22, the territory government hoped to put a proposal for the project to federal parliament next year.
They would then have undertaken procurement next year and started construction in late 2020-21.
Now Mr Barr said a realistic timeframe for operations was about 2025.
"I'm conscious now ... I won't be able to get the really quick continuity I was hoping for in terms of rolling into an expansion of the project but we'll have a look at our options and I might have a surprise announcement or two coming up," Mr Barr said.
"We'll also need to kick along Canberra's construction sector over the next period so you can look to a big program of infrastructure in health, in schools ... and transport initiatives."
Canberra Liberals leader Alistair Coe said Labor's $200 million "gift" was purely political.
"The ball is now in the ACT government's court to convince the Coalition government that this project stacks up and the best way to do that will be to have a sound business case that clearly details the benefits that are going to be derived as a result of this project," Mr Coe said.
But light rail is not the only area where the election has thrown a spanner in the works.
Next month's territory budget will be more restrained and the mid-year budget review will be bigger because of uncertainty over the Coalition's policies, Mr Barr said.
The ACT will also bring forward its land release program, with the abolition of stamp duty and the Coalition's first home loan deposit scheme expected to fuel demand from first home buyers.
"Clearly we're not going to see changes in negative gearing so investors are going to be in the market as well and I'm very keen to ensure first home buyers through our stamp duty cuts get an opportunity to get into the housing market," he said.