HARRISBURG, Pa. — The union that represents about 10,000 guards in Pennsylvania’s state prisons told Gov. Tom Wolf Thursday it plans legal action to stop his effort to force them to get COVID-19 vaccines over the next month.

The president of the Pennsylvania State Corrections Officers Association sent a letter to the Democratic governor two days after Wolf ordered the guards and some other state workers to get fully vaccinated by Sept. 7 or face weekly testing.

Union president John Eckenrode told Wolf his policy announcement was “a slap in the face — and frankly, way too late because thousands of our members already have been infected, due to your inaction.”

“This is the latest episode of what has been a woefully inconsistent vaccination/testing/masking policy by this administration in our state prisons,” Eckenrode wrote, adding the union “has instructed legal counsel to challenge this latest proposed policy change.”

Wolf press secretary Lyndsay Kensinger said Thursday the initiative was designed to protect the guards, their families and the people they work among.

“The union exists to protect and support the employees it represents, so the corrections union’s opposition to this initiative to stop the spread of COVID-19 is extremely disappointing,” Kensinger said.