New Safeway locations joined UFCW Local 7's strike efforts on Monday, bringing the total to six locations across the state with more expected in the coming days.

Among the hundreds of union workers already on strike is Castle Rock store clerk Tanner Vonstein. Vonstein says he voted to support the strike after five years with the company.

"I know it's really important that if we're together, then we can win this fight," Vonstein said.

While shoppers may remember the recent strikes across Colorado King Soopers locations, UFCW Local 7 says this is the first Safeway strike in 29 years. The union says the strike comes to address what it says are unfair labor practices from Safeway.

"I was doing the job of four people by myself. I mean, I'm a front-end head clerk, and I was doing produce for about eight months," Vonstein said. "It's very stressful."

While dozens of shoppers continued to cross the picket line in Castle Rock on Monday, some turned away after hearing stories like Vonstein's.

"I can barely afford rent on what we have now, and with these minimum wage increases, it doesn't make it any easier for me," he said.

And from Estes Park to Castle Rock, UFCW Local 7 President Kim Cordova spent the day driving across the state and bringing workers to the picket lines with more expected to join this week.

"As well as workers walking off the job, the entire state of Colorado, all of the union stores, and the union workers inside, they are so upset with their employer they're ready to strike this entire state," Cordova said.

But some shoppers are asking how long this strike could last.

"They haven't resolved the unfair labor practice charges that we have against them, so we're still far apart, and the strike is going to continue to grow until we reach a contract with them," Cordova said.

In a statement, however, Safeway disputed claims of unfair labor practices and shared the following statement, in part:

"Safeway in Colorado remains committed to productive discussions with UFCW Local 7, and we are disappointed the union has chosen to strike some of our stores. We respect the rights of workers to engage in collective bargaining and are negotiating in good faith to achieve a balanced agreement that rewards our associates, benefits our customers, and is sustainable for our company in the competitive grocery industry."

But as negotiations continue, Cordova says so too will the strikes.

"You may see, it could happen today, it could happen tonight. It can happen tomorrow, but the strike is going to expand until we reach a contract," Cordova said.

Cordova explained that as negotiations continue with King Soopers as well, it could be possible that both chains eventually strike at the same time, but emphasized that the focus right now is on Safeway.

In its statement, Safeway also said that it expects stores to remain open for customers throughout the strike.