Thousands of AT&T Wireless workers could be walking off the job today.
On Friday, the Communications Workers of America gave the company 72 hours notice about a possible walk out.
CWA members have yet to stroke a deal with AT&T on extending labor contracts.
Negotiations have been underway since early February.
About 50% of employees covered by the contract work in the AT&T Call Centers, around 40% work in the company's stores, and 10% are technicians.