First they were told to prepare to pack their bags and move to Wagga Wagga, now Commonwealth agricultural research workers in Canberra must apply for their own jobs.

Other specialists at the Grains Research and Development Corporation are being forced to take a pay-cut while yet another group have been told their jobs are re-locating interstate and it is not negotiable.

The corporation, which is a key part of the Coalition government's plan to decentralise a group of research agencies to various locations around the country, confirmed that "difficult but necessary" decisions had been made about its workforce.

According to workplace union Professionals Australia, 33 GRDC workers, or about half the organization, were told their jobs have been "spilled" and that they would have to apply for changed roles within a week.

Some of the new jobs will be based in NSW, and some as far as Queensland or West Australia.

"This includes the jobs of employees that have only recently moved to the GRDC who were given no indication this was in the wind," union official Dave Smith said.

"Some of the employees that have been told that their jobs haven't been spilled have nonetheless been told that they will be paid less despite their roles being ongoing."

Mr Smith said his union would be taking its unhappiness to industrial umpire the Fair Work Commission, saying the approach of GRDC management to the restructure was unacceptable.

"There is no consideration of the implications on the lives of employees and their families let alone the research programs that they are deeply committed to commissioning and oversighting and for which they have a strong and successful record," Mr Smith said.

A spokeswoman for the corporation said the move was a response to an external review of its "operations, structure, systems, processes, outcomes and outputs to benefit the grains industry in Australia."

"There will be a number of redundancies of current positions as the GRDC transitions to the new structure, with several positions to be redesigned as part of a focus on delivering greater value to Australian grain growers for their investment," she said.

"The external review identified the need for structural reform to more closely align with both industry and government agendas.

"This is a difficult but necessary decision and the GRDC is working closely with those affected to support them through this process."