( CNN ) -- The ongoing labor dispute between the professional basketball players ' union and the league ratcheted up a notch Tuesday as the NBA said it filed a lawsuit against the players . The NBA also announced Tuesday that it has filed an unfair labor practice charge with the National Labor Relations Board along with the lawsuit , which was filed in federal court in New York . These moves have one NBA expert saying the labor struggle is putting the start of the NBA season in danger . `` This is just one more log on the fire that is threatening to consume the whole NBA season , '' said David Aldridge , a reporter for NBA TV . `` I am not optimistic that season will start on time . '' Both actions are reactions to recent threats by the players ' union that were hampering negotiations , the NBA said in a statement . `` These claims were filed in an effort to eliminate the use of impermissible pressure tactics by the union which are impeding the parties ' ability to negotiate a new collective bargaining agreement , '' said NBA Deputy Commissioner and Chief Operating Officer Adam Silver . The NBA began a lockout of its players in early July . NBA Commissioner David Stern has argued that the last season was not profitable for most of the league 's 30 owners and there was a need for some cost-cutting help from players . The league lost as much as $ 300 million in the 2010-11 season , Stern has said . One of the battles has been around the owners not agreeing to the players union 's call for an average $ 7 million player salary in the sixth year of a new labor deal . The current salary average is about $ 5 million . Aldridge said other big issues are a fight over whether the NBA will strengthen its salary cap and a move by the owners to get a bigger share of revenues . The last work stoppage occurred in 1998 .
The NBA has also filed an unfair labor charge with the National Labor Relations Board . NBA official says claims are meant to `` eliminate the use of impermissible pressure tactics '' NBA expert `` not optimistic that season will start on time '' and prevent players from being paid for work they do outside their contracted hours, which could be detrimental to team performance ;