Senator Katy Gallagher has grilled the Finance Department over the Immigration Department's bid to potentially move out of Belconnen, demanding an end to uncertainty at Senate estimates on Thursday.
The new senator said the departments did not yet have a way to consider how a potential move, so far derailed by "project tetris", would hit Belconnen businesses.
In January, Immigration put out a tender for 80,000 square metres of building space within a 10-kilometre radius of Capital Hill, signalling a move out of Belconnen.
"Project tetris", Finance Minister Mathias Cormann's label for his new policy favouring filling already leased Canberra office space as opposed to leasing new buildings, has now placed that move under a cloud.
"Instead of having large areas sit vacant and individual departments moving into new tenancies, we want to ensure that there are no gaps," Senator Cormann said.
Finance Department secretary Jane Halton agreed that Immigration's bid to move would not escape project tetris's wrath.
"Departments won't be able to always do the thing that they would like to do most, which is about them," she said.
"Because at the absolute base level then if it isn't for the collective good then sometimes then people are going to have to take options which are also robust in the long term."
Under questioning from Senator Gallagher, the department's acting deputy secretary, John Edge, said the uncertainty over Immigration's tender process had not been sorted out.
"We are currently in discussions with Immigration about how that part of the process will be resolved but we have not resolved that at this point," he said.
Ms Gallagher then questioned whether "project tetris" would undermine the tender's level playing field for bidders, and cause delays.
"The original tender process had the move under way by 2017 ... One would assume though, if new buildings has to be built as part of the tender, then 2017 is starting to be looming," she said.
Department staff responded saying the process involved discussions with Immigration and they not comment on whether it would push out the deadline.
Ms Gallagher said the process was not providing much certainty to the community.
"In terms of the Immigration tender, there is a lot of uncertainty at this point in time," she said.
Senator Gallagher also appeared sceptical of the department's ability to properly consider the potential impact of the move on the town centre, peppering the department with questions.
"So with, project tetris and the announcement that local impact would be part of that, and would be part of Immigration and the assessments, how are you going to do that when they are in a tender process?" she said.
"So you don't really know how you are going to assess local impact?"
Ms Halton responded saying they were only in the preliminary stages of their discussions with Immigration.
"We are moving as fast as we can, that's probably the best I can say to you," she said.
ACT Liberal senator Zed Seselja, who was also at the hearing, rose the prospect of the car park next door to a Belconnen Immigration building possibly being owned by the Commonwealth, providing an alternative to the move.
None present could confirm this.
Meanwhile, the committee examined the Finance Department's own desire to move into a shiny new office at 1 Canberra Avenue.
Ms Halton ruled out a move to hot desking, saying it was too "impersonal" and they would instead go for a "fixed and flexible" approach.
"Everyone needs a buffer, and I have told the staff they don't need to worry about that or worry that I'm going to sit next to them," she joked.