Liberal Senator Zed Seselja and NSW Nationals leader John Barilaro say the Coalition's decentralisation agenda is "incorrectly focused" on Canberra, and public servants should instead be parachuted from overcrowded Sydney and Melbourne into the bush.
But decentralisation minister Mark Coulton says the idea that the nation's capital would be disadvantaged if a small number of jobs were moved to Darwin or Armidale was "bit of a stretch, quite frankly".
Senator Seselja and Mr Barilaro last month wrote to Mr Coulton and Nationals leader Michael McCormack to plead for jobs to stay in the capital region.
"We understand the importance of jobs to regional Australia however the current policy of endeavouring to move public service departments from Canberra gives a boost to some regions at the expense of ours," they wrote.
"A push to decentralise the public service and provide an economic base in regional Australia is incorrectly focused on the national capital region and should instead focus on decentralisation from large, congested cities such as Sydney and Melbourne.
"Decentralisation from larger cities is able to provide the benefits to regional Australia that you are seeking while only having a minimal effect on the community and the local economy."
Senator Seselja and Mr Barilaro also said it was vastly cheaper to rent office space in the Canberra region than other capital cities.
"Sydney has an average net effective rental rate of around $545 square meres compared to Canberra which has average net effect rental rate of only $288 metres square per annum," their letter said.
"In addition to the massive cost differential, moving public servants from large cities such as Sydney and Melbourne has the added benefit of taking pressure off these congested cities.
"We would encourage you to seriously consider the consequences [to] regional communities in the Canberra region before any further decentralisation decisions are taken.
"We also stress the importance of proper local consultation before any further decisions are taken to decentralise more public service positions."
But Mr Coulton said the region's representatives needed "a bit of a reality check".
"Canberra is under no threat from our decentralisation agenda," Mr Coulton said.
"I love Canberra, I'm a part-time resident and it has so much to offer but I do get a little amused sometimes when I hear the representatives from Canberra with their crocodile tears about how tough things are, considering the towns I represent are doing it incredibly tough at the moment.
"Quite frankly anyone who thinks Canberra is suffering under the current climate should step out of Canberra a little more. Canberra has a strong economy, there's buildings going up everywhere. The idea that regional Australia could potentially suck resources out of Canberra is quite strange."
Mr Coulton, who took over the portfolio in May from Nationals deputy leader Bridget McKenzie, said their plan for decentralisation was about "placing public servants near where their work is".
He said recent relocations of the Murray Darling Basin Authority to Menindee or the Office of Maritime Safety to Coffs Harbour, as well as the opening of Department of Infrastructure offices along the inland rail route, were examples of decentralisation done right.
"Placing Commonwealth jobs in areas where they can be more effective makes sense," Mr Coulton said.
"Why would you run a Maritime Safety Authority a couple of hundred kilometres away from the water?"
About 57,000 of the Commonwealth's 150,000 bureaucrats call the nation's capital home, according to 2018 figures.
But the ACT has lost one in 10 of its federal public service jobs since the Coalition came to power in 2013.
And a question mark remains hanging over the future of public service agencies in Canberra, after top bureaucrats were told in 2017 to justify their department's continued presence in Canberra and other capital cities.
In February, the government accepted the findings of a parliamentary inquiry that the location of federal agencies should be re-assessed whenever a new one is created or merged, or before a lease is renewed.
Mr Coulton said he agreed with that policy, although no relocations were under consideration at the moment.
The inquiry was sparked by the controversial relocation of the Australian Pesticides and Veterinary Medicines Authority from Canberra to Armidale.
The pesticides authority convinced only 12 Canberra-based staff to move with it to Armidale, bringing the redundancy bill for public servants refusing to relocate up to $2.4 million.
But Mr Coulton said he believed history would show the APVMA move was "not a bad idea after all".
"I haven't been up there myself but from secondhand reports there's been very strong interest in those jobs, many applications and it's doing a great job up there in Armidale," Mr Coulton said.
Mr Coulton said regional Australia had enormous potential that was not being met due to skill shortages. His "stamp" on the decentralisation portfolio would be to pursue it in a "holistic way" - bringing skilled migrants to regional areas and encouraging businesses to relocate as well.
"It's not just about moving federal government departments," Mr Coulton said.