Opponents of the Trump administration’s plan to break up the Washington, D.C., headquarters of the country’s public lands bureau are warning of a brain drain, saying many staffers who are being reassigned are opting to quit rather than move out West.

U.S. Interior Secretary David Bernhardt defended the move Friday. Opponents have projected that the number of Bureau of Land Management staffers agreeing to move from headquarters could be as low as 15%, which Bernhardt said was “not consistent with what I’ve seen.”

The deadline for most staffers to notify the land bureau, which is overseen by the Interior Department, whether they intended to move was Thursday. But the bureau had not yet compiled a count for how many staffers had so far agreed to relocate, spokesman Derrick Henry said.

Bernhardt has called for about 300 positions to be switched from Washington to other offices in 11 Western states, including Nevada, Arizona and Utah. About 25 will be going to the new headquarters in Grand Junction, Colorado.

Former bureau employee George Stone, director of the Public Lands Foundation, said the rationale that the move will give Western residents, county commissioners and elected officials better access to federal decision-makers doesn’t make sense because most of the agency’s 10,000 employees are already in field offices outside Washington.