Dec 19 (Reuters) – The U.S. National Labor Relations Board on Friday filed complaints against McDonald’s Corp and its franchises for alleged labor violations, including the illegal firing and intimidation of staff who protested working conditions.

NLRB General Counsel Richard Griffin filed complaints in 78 cases against the company and its franchisees from New York to Los Angeles, the board said.

The complaints claim the franchises illegally fired or intimidated workers for taking action or making statements aimed at improving their wages and working conditions, including participating in nationwide protests.

McDonald’s workers have engaged in a series of strikes and protests to call for improved working conditions and a $15 minimum hourly wage.

A McDonald’s spokeswoman said the company and franchises would fight the charges.

“These allegations are driven in large part by a two-year, union-financed campaign that has targeted the McDonald’s brand and impacted McDonald’s restaurants,” the spokeswoman, Lisa McComb, said.

The complaints will be considered by administrative law judges beginning in March 2015. They can then be appealed to the five-member NLRB.

The complaints follow Griffin’s announcement in July that McDonald’s and its franchises would be treated as joint employers in the cases, meaning the company can be held liable for labor violations by the franchises.

McComb said that decision “improperly and dramatically strike(s) at the heart of the franchise system.”

(Editing by Bernadette Baum)