MONTGOMERY, Ala. (AP) — More than 17,000 AT&T workers in nine states across the Southeast are on strike after accusing the company of unfair labor practices during contract negotiations this summer.

The Communications Workers of America — the union representing the striking employees — said workers walked off the job Friday in response to AT&T’s failure to bargain in good faith. Workers have been attempting to reach a new contract since June. The labor organization said AT&T did not send representatives to the bargaining table who had authority to make decisions and that the company has reneged on agreements made in bargaining.

“Our union entered into negotiations in a good faith effort to reach a fair contract, but we have been met at the table by company representatives who were unable to explain their own bargaining proposals and did not seem to have the actual bargaining authority required by the legal obligation to bargain in good faith,” Richard Honeycutt, vice president of CWA District 3 in the Southeast, said in a statement.

The strike involves AT&T technicians, customer service representatives and others who install, maintain and support AT&T’s residential and business wireline telecommunications network. It involves workers in Alabama, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee

The union said it filed an unfair labor practice complaint with the National Labor Relations Board.

AT&T denied the union’s accusations.

“CWA’s claims of unfair labor practices are not grounded in fact. We have been engaged in substantive bargaining since Day One and are eager to reach an agreement that benefits our hard-working employees,” the company said in emailed statement. AT&T said it reached three separate agreements this year covering more than 13,000 employees.

The labor union on Monday also accused AT&T of “sending undertrained managers and contractors to perform highly technical work” during the strike. AT&T said it has “various business continuity measures in place to avoid disruptions to operations and will continue to provide our customers with the great service they expect.”