The longstanding relationship between the US government and Blackberry may have come to an end. A memo from the Senate Sergeant at Arms sent last week to administrative managers, chief clerks, and system administrators indicated this much.

According to the memo, BlackBerry told telecom carriers Verizon and AT&T that production of all Blackberry OS 10 devices (Q10, Z10, Z30, Passport and Classic) is being discontinued and future fulfillment can’t be guaranteed.

BlackBerry also said it is discontinuing the production of the Classic version of its phone. This move raises further doubts about the future of the smartphone pioneer’s handset business, which has been on a downward spiral, even as the company shifts its focus to software.

BlackBerry’s stock fell more than 4 percent after an executive confirmed the move in a blog post. BlackBerry launched the Classic less than two years ago, with the hope that it would catch on among customers who wanted a physical keyboard in a world of touchscreens.

Senate staffers can use the remaining phones in stock (about 600), and will continue to receive uninterrupted warranty and technical support, for the “foreseeable future,” the memo said. Staffers can also transition to Samsung S6 Android phones or Apple’s iPhone SE, according to the memo.