Staff from Galway City Council will hold a protest on Monday against the controversial move to Crown Square.
They claim they weren't consulted - and Fórsa Trade Union says it's a move that "nobody wants".
The deal to move City Hall from College Road to Crown Square in Mervue was signed-off in 2022.
But three years later, the move hasn't happened and there's still much work to be done, with some predicting the final cost could be up to €30m more than originally planned.
And staff too, have taken issue with the move - saying there was no consultation with them, or with the public.
Fórsa Trade Union says three quarters of staff surveyed have indicated the move would make them consider getting a job elsewhere.
It's now arranged a protest at City Hall on Monday afternoon at lunchtime, ahead of a meeting of city councillors.
Although councillors backed the move in 2022, many have since expressed regret and a sense of having been misled - with some saying they were "sold a pup" on Crown Square.