Workers tasked with road maintenance, litter collection, sports ground maintenance and park mowing in the ACT could walk off the job in weeks after pay talks with the government stalled.
The CFMEU said strikes could begin in the coming weeks if pay talks don't progress after 300 of its members voted in a protected action ballot, with 99 per cent supporting industrial action.
The general service officers want a 5 per cent pay rise this year, followed by 4 per cent in 2027 and 3 per cent in 2028, along with a pay allowance for front-line workers, the union said.
The ACT government is offering 3 per cent a year over three years.
"The workers who maintain Canberra deserve to be able to afford to live in the city they help keep running," CFMEU ACT assistant secretary Michael Hiscox said.
"This isn't a step workers want to take but is one they've been forced into after the ACT government has knocked back their reasonable requests."
The union said the government had repeatedly rebuffed the workers' reasonable requests in enterprise bargaining and industrial action could halt "road maintenance, litter collection, sports ground maintenance, park mowing and maintenance of ACT government facilities".
"Our members are part of this community as well and don't want disruptions to their services either, which is why we continue to seek an agreement before taking industrial action," Mr Hiscox said in a statement on Friday.
The lowest-paid general service officers secured a 34 per cent pay rise over three years in 2023 and agreed at the time to a deal that was set to push their pay from just under $51,000 a year to more than $68,000.
The ACT government is under growing pressure from unions as it works to reach agreement on new enterprise agreement with its staff.
A full-day public school teachers' strike earlier this month forced schools to close and the Australian Education Union has warned action could escalate in the third term if the pay and conditions talks are not resolved.
More than 95 per cent of ACT government staff represented by the Community and Public Sector Union who voted in a protected action ballot endorsed industrial action in May, with Housing ACT staff walking off the job for an hour in May.
The government has proposed pay rises of 3 per cent a year over three years, which the CPSU said was a "disgraceful" offer set below inflation.
The government's offer also includes removing the cap on family, domestic and sexual violence leave, doubling the entitlement to paid Aboriginal and Torres Strait Islander ceremonial leave and reproductive leave to 10 days, and providing new leave entitlements for parents who experience pregnancy loss.
