Mr Barr wrote to Prime Minister Malcolm Turnbull on Friday, asking him to keep an April 2015 commitment made by his predecessor, Tony Abbott, to stop cuts to the national capital amid the latest news of Commonwealth budget savings.

He accused the federal government of failing to give Canberra and the public service a fair go, as incoming deputy prime minister and new Nationals leader Barnaby Joyce flagged moving three ACT-based research organisations out of the capital, in the same week job losses were touted across cultural institutions and at the CSIRO.

On Friday afternoon Mr Turnbull's office said it was yet to receive the letter, but it could reach the Prime Minister's desk by Tuesday or Wednesday.

"It is concerning that in the space of a few days, our national institutions have come under attack, government research jobs have been ripped out of Canberra and heads of departments are threatening to move senior roles to other cities," Mr Barr wrote.

About 350 CSIRO staff are expected to lose their jobs nationally, including Canberra staff working in the Land and Water unit. A small number of staff from the Oceans and Atmosphere unit could also go.

Job losses were forecast in Senate estimates hearings this week, as institutions including the National Museum of Australia, National Portrait Gallery, Museum of Australian Democracy, National Film and Sound Archive, National Gallery of Australia and National Library face a $20 million savings drive. Some savings could be made from operations but the hearing was told some job losses were inevitable.

Organisations moving from Canberra include the Barton-based Grains Research and Development Corporation, which will have four offices at Dubbo, Toowoomba, Adelaide and Perth. The Rural Industries RDC will shift its main operations to Wagga Wagga and the Fisheries Research and Development Corporation, based in Deakin, will establish a new regional office in Adelaide.

Mr Barr's said tourists and visitors to Canberra's national institutions support jobs in the ACT. He talked up the territory's efforts to diversify the local economy, including through securing direct international flights to Singapore and Wellington and echoed calls for industry assistance packages made by former chief minister Katy Gallagher.

"Our economic successes are eroded by continually needing to counter the impacts of the Australian government's reduction of jobs," Mr Barr wrote.

"Other jurisdictions receive Australian government support for declining industry sectors, such as the car industry in Adelaide and Geelong and the steel works in Wollongong. It's disappointing that similar support is not forthcoming when job cuts ... hit Australian workers in Canberra."

Mr Abbott oversaw the loss of about 15,000 public service jobs during his two years in office, leaving the federal bureaucracy with fewer staff than in the last months of the Howard government in 2007. The Coalition said it would cut at least 12,000 jobs in government through natural attrition, but tight restrictions on recruitment were quickly imposed.

Mr Barr said federal government assistance could come in the form of funding for the extension of the light rail line to Russell Defence precinct or for the development of a space economy in Canberra.

Both ideas would "strongly align with [Mr Turnbull's] innovation and sustainable transport policies".

Mr Barr has written to outgoing Transport Minister Warren Truss to outline the benefits of federal funding for the 3.2 kilometre extension to the first stage of the light rail line. He said trams to Russell would provide immediate financial benefits for the Commonwealth through increases in value to its undeveloped land holdings worth about $85 million.