Verizon Communications workers picketed again Friday afternoon and headed closer to the brink of a strike, less than a week after they backed down from one.

With talks hung up over job security issues, union officials have set another strike for 12:01 a.m. Monday. Last weekend, the Communications Workers of America and the International Brotherhood of Electrical Workers, which together represent more than 65,000 Verizon employees from Massachusetts to Virginia, postponed a scheduled strike, citing progress in negotiations. The unions’ five-year pact expired Aug. 2.

“We’re ready [to strike] and we’re serious. If we have to do it, we will,” CWA Local 1118 Executive Vice President Len Welcome said.

Just as they did a week earlier, CWA Local 1118 members picketed Friday outside the company’s regional headquarters on State Street, where the union has about 500 members. In the Capital Region, CWA has 1,500 members, who include field technicians, accountants and clerical and customer service workers. Regionwide, IBEW Local 2213 has 150 business office workers.

The unions are growing increasingly concerned over Verizon’s greater reliance on non-union workers. CWA said the telecom has shed 14,000 organized workers over the past five years. In Albany, Welcome said CWA is especially concerned about the job security of 300 repair and installation call center workers.

In announcing a decision to “stop the clock” last Sunday, CWA reported progress in talks over health care, retirement security and strengthening job security provisions in the pact. “Where all the obstacles we’re having is job security,” Welcome said.

“We are very surprised, given the situation. We and union leadership have been making consistent progress and have resolved most of the important issues,” Verizon Chief Communications Officer Peter Thonis said.

The last time CWA/IBEW workers struck was in 2003. Organized Verizon workers are not strangers to strikes, as they have engaged in seven over the past 27 years.