An unexpected surge in staff resignations at the national pesticides authority is putting "significant pressures" on those remaining ahead of its forced move to Armidale.
The Australian Pesticides and Veterinary Medicines Authority predicts its approvals of new products will slow during the relocation, when more staff are expected to leave, others prepare the agency for the move, and new recruits are trained.
"The APVMA is experiencing higher than expected staff departures," it said.
Twenty regulatory scientists and an additional 28 staff members, with 204 years' service between them, left the agency between July and February.
The APVMA told a Senate inquiry into the relocation, a signature policy of Nationals leader and Deputy Prime Minister Barnaby Joyce, a list of risks related to the move included the potential to make "inappropriate decisions" resulting in "significant harm, loss or liability".
Staff wellbeing, financial sustainability and its ability to deliver on obligations under government legislation were also potentially at risk.
"The pressures on staff resulting from staff departures is also significant," the APVMA told the Senate committee.
Unfinished assessments, covering new products and permits, grew by 150 to 1,300 at the end of December compared to the same month in 2015, and the number of overdue applications also climbed.
The APVMA is looking at graduate programs, employment agencies, digital connection of remote employees, and contractors to fill gaps expected after the relocation.
New recruits had signalled they were willing to relocate to the northern NSW town, the APVMA said.
It's drawing on a pool of 200 applicants from a recruitment round late last year to fill multiple vacancies across the agency.
When Mr Joyce wrote to APVMA chief executive Kareena Arthy flagging the move in 2015, she replied she was unable to support the proposal at that time "due to the magnitude of expected losses of expertise and experience", the agency told the Senate inquiry.
A spokesman for Mr Joyce said the agency was failing to meet recommended processing timeframes from Canberra.
"Why would anyone fight to preserve a model that currently isn't meeting required legislated timeframes?", he said.
Staff surveys in 2015 and 2016 showed less than 10 scientists were willing to uproot from Canberra to Armidale.