NEW YORK (Reuters) -The U.S. Securities and Exchange Commission has told unionized employees they will have to return to the office in mid-April, unless they have certain exemptions, according to a memo seen by Reuters.

The move follows similar efforts at the agency with its non-union staff, as well as across the federal workforce, in response to a mandate by Republican President Donald Trump that officials terminate remote or hybrid work arrangements.

Citing that directive, guidance from the Office of Personnel Management, SEC Chief Operating Officer Ken Johnson said in a memo to all staff they will be required to work on-site beginning April 14, 2025, the SEC's February 25 memo said.

He also said the return-to-work directive would "best position the SEC to fulfill the agency's mission."

The SEC did not immediately respond to requests for comment. The head of the National Treasury Employees Union Chapter 239, which represents SEC employees, also did not respond to requests for comment.

But in an email to members seen by Reuters, the union said the SEC's action "plainly violates" the union contract and called the order illegal.

"Like you, the union only received notice of this order by the SEC management moments ago," the email said.

The union's 2023 collective bargaining agreement outlines telework options for approved employees. That agreement lasts three years.

The NTEU's national office declined to comment.

The union said in its email that it will ask the SEC to rescind the directive, clarify it does not apply to members of the union, and admit it violated the statute, among other requests.

Still, it told members to prepare to return to work on April 14.