May 9 (Reuters) - Tesla has been accused by a U.S. labor agency of discouraging workers at a Buffalo, New York assembly plant from union organizing by barring them from using phones and other devices, an agency spokeswoman said on Thursday.

A National Labor Relations Board (NLRB) official issued a complaint late Wednesday claiming Tesla's workplace rule banning personal technology use, recording, and storing or sharing content violates U.S. labor law, according to the spokeswoman, Kayla Blado.

Reuters could not immediately obtain a copy of the complaint.

Tesla did not immediately respond to a request for comment.

The case will be heard by an administrative judge whose decision can be appealed to the five-member labor board and then to a federal appeals court. An initial hearing is scheduled for July, Blado said.

The United Auto Workers union has tried for years to organize Tesla factory workers, and in November announced a renewed push to organize non-union plants across the country. (Reporting by Daniel Wiessner in Albany, New York; Editing by David Gregorio)