Union president Charles Cerf said a prime issue was that the airline proposes to replace up to 20 percent of its members with temporary or contract workers as attrition occurs. The 9,400 union members nationally are Southwest employees.
“Outsourcing work to people who only indirectly work for Southwest Airlines won’t give the same high quality of customer service that we provide,” Cerf said in a telephone interview.
A spokesman for the airline said the company would not comment on the outsourcing issue. But he said that the airline was actively participating in negotiations and that it supported its employees’ rights to express themselves.

Cerf said the union had been negotiating for a new agreement since July 2011, and many members had not received a raise since then.