Washington (CNN) An overwhelming number of US Department of Agriculture employees who have been reassigned from Washington, DC, to the greater Kansas City area may instead leave the department, according to surveys conducted by the union representing them.

Such losses among the more than 540 USDA research employees affected by the reassignment could result in a drain of institutional knowledge and talent at two agencies that either fund agricultural research across the nation or produce crucial reports, including data on agricultural markets, as well as 10-year projections for the farm sector and estimates of US and international agricultural productivity.

Agriculture Secretary Sonny Perdue and the department have argued that the move will lower living costs, save taxpayer dollars and move the agencies closer to "stakeholders." But many employees at the two affected agencies, the Economic Research Service and National Institute of Food and Agriculture, view the change as politically driven and a way to disrupt climate research and other work with which their bosses disagree by pushing out experienced personnel.

Out of the roughly 250 ERS researchers and economists being reassigned, at least 69% have said they are definitely not moving, while 87% have said they won't or likely won't move to Kansas City, according to one of the surveys conducted by the American Federation of Government Employees. Out of the 294 NIFA employees slated to relocate, at least 71% have said they will not move, according to the survey, which was released last week.

They have until Monday to decide whether to make the move but remain in the dark about their final location in the greater Kansas City area -- including which side of the Kansas-Missouri state line they will be on. If they accept the move, employees must be ready to show up for work by September 30.

On Monday, the USDA rejected the union's proposals, which included allowing employees to telework for up to a year or allowing employees with a "hardship" reason to remain in the capital region.

"Concerning the demands in their entirety, the Agency declines to agree to any proposal that would precondition the exercise of any management rights on the completion of bargaining. Nor will the Agency delay the implementation of any management action that is necessary for the functioning of the Agency," the letter states.

Peter Winch, an AFGE union representative helping lead negotiations, described the department's response as a "stall tactic."

The department has not responded to two extension requests from the union, which included letters from 49 employees.

Employees from both agencies turned their backs to Perdue in protest at an all-hands meeting last month when he announced the final location for the move.

"We are currently being forced to relocate, quit or be fired," Kevin Hunt, acting vice president for the ERS union, told CNN. "This is devastating the current science the Economic Research Service produces and puts into question if any current research sees the light of day. The secretary must reverse course immediately and come to the bargaining table now or the American farmer will lose their voices in Washington and American taxpayers will be billed to fix what the secretary broke."

A USDA spokesperson said the department will not know employee decisions until Monday.

"In the meantime, we are doing everything we can to ensure employees have the resources and information to make their decisions and to implement the transition smoothly and efficiently to ensure mission critical work can continue," the spokesperson said.

But Wesley Dean, acting vice president for the NIFA union, is concerned that moving NIFA could affect the agency's ability to allocate grant funding. NIFA funds agricultural, climate and economic research across the nation -- including the Bee Informed Partnership, which is now the only national survey to keep track of honeybee loss after USDA decided to suspend its own annual bee colony survey earlier this month. Honeybees pollinate one in three crops and play a crucial role in the agricultural system, but their populations have plummeted in recent years.

"Moving a granting agency at the end of the fiscal year will have a detrimental impact on getting grant money out the door to our stakeholders," Dean said. "Our staff, with all their years of experience, are leaving for other agencies. We should be focused on this, rather than hastily moving the agency."

Former USDA officials and scientific and agricultural associations have come out against the plan, arguing that it may push trained staff out the door and pose a risk to the agency's independent and objective analysis.

"ERS is ranked as number three in the world of institutions in the field of agricultural economics, a reflection of our leadership in economic research," 56 former USDA officials wrote in a letter submitted to Congress. "This proposal puts a world-renowned research agency at risk and could set back the federal statistical system at a time when the United States should be leading the world in innovation."

The move could also be blocked by Congress. A provision in the Financial Services and General Government spending bill that passed last month included an amendment from Rep. Eleanor Holmes Norton that would block the General Services Administration from using its funds to relocate ERS and NIFA.

The USDA's inspector general is also investigating whether Perdue has the legal authority to move the agencies.