Federal regulators are expected to announce their verdict on the planned $4.3 billion merger of United, the world's largest airline, and US Airways on that date.
The Association of Flight Attendants is opposing the merger while it is in reopened contact talks with United. The flight attendants had agreed to a 10-year contract in 1997, but they demanded the contract be re-examined last year after industry-leading pay raises were given to the carrier's pilots.
Union leaders said United must get a limited waiver for the merger from the flight attendants, whose contract prohibits the airline from owning and operating another airline.
AFA President Linda Farrow says her union has been negotiating in good faith with United to prevent a major dispute, but said the airline ''has refused to take the talks seriously.''
Dawn Deeks, spokeswoman for the AFA, said the union broke off talks with the airline last week after United offered a 4 percent raise to the attendants and did not offer job security, something the airline gave its pilots.
''While management has promised flight attendants raises based on standards applied to the pilots, their actual proposals have fallen far short of that goal,'' Farrow said.
The leadership of the flight attendants union plans to meet Thursday to decide initial plans for a strike, including scheduling a vote of its 25,000 members, Deeks said.
Deeks said the strike is allowed because the flight attendants are not in traditional contract negotiations with the company, therefore the National Mediation Board is not involved and a 30-day ''cooling off'' does not apply.
United spokeswoman Whitney Staley disagreed.
''Any strike or slowdown by the association or its members is a violation of the Railway Labor Act,'' Staley said. ''Last week, we notified the AFA that if any illegal activity occurs, United will take every step necessary to protect our customers. That includes pursuing legal actions and sanctions against the union.''