Governors from five states have called on the Department of Defense to rescind its vaccine mandate for members of the National Guard that can see noncompliant service members dismissed from their posts.

In a letter to Secretary of Defense Lloyd Austin sent on Tuesday, the governors acknowledged his authority to set "readiness standards" for uniformed military service members, but argued that he was overstepping his authority with the COVID-19 vaccine mandate by interfering with their authority as commanders in chief of their states' National Guard units.

“Directives dictating whether training in a Title 32 status can occur, setting punishment requirements for refusing to be COVID-19 vaccinated, and requiring separation from each state National Guard if unvaccinated are beyond your constitutional and statutory authority,” they wrote.

Unless activated for federal service, the National Guard answers to the governor of their respective state. These dueling lines of authority have been at the center of the fight that started with Oklahoma Gov. Kevin Stitt’s order to guardsmen under his command to reject the vaccine mandate, putting their pay and careers at risk.

The governors behind the letter represent Iowa, Nebraska, Alaska, Mississippi and Wyoming, and they are all Republicans like Gov. Stitt. GOP governors have encouraged vaccinations, but they have refused to issue mandates and challenged those introduced by the Biden administration via executive order.

“The federal government continues to overreach further into the lives of Americans and especially those serving our country and protecting our very freedoms,” said Gov. Kim Reynolds of Iowa in a statement.

“ It’s unconscionable to think the government will go so far as to strip these honorable men and women of the nation’s top duties if they don’t comply. They protect the very freedoms that the federal government apparently doesn’t believe they too deserve,” she continued.