The battle for higher wages took another turn Tuesday as Twin Cities janitors and security guards said they are prepared to strike beginning Sunday, unless employers agree to a new labor contract with better wages.

The Service Employees International Union (SEIU) Local 26, which represents more than 6,000 local janitors and security officers, said both groups of workers have worked without renewed contracts since Dec. 31.

The SEIU janitors and guards work for contract maintenance firms hired to clean and protect corporate buildings such as Target Corp., Wells Fargo Center, Medtronic and U.S. Bancorp Bank Plaza.

Javier Morillo, president of SEIU Local 26, acknowledged that bargaining talks have continued between employers and the janitors and guards. But employers have not addressed major concerns such as "massive cuts to wages and benefits," he said.

"Although these hardworking Minnesotans provide these corporations with millions in profits, they are forced to live in poverty."

Sunday's strike date is the same day that about 400 local retail janitors have chosen to walk off the job unless their employers agree to begin discussions that would allow them to organize a labor union.

Unlike the SEIU janitors, the janitors who clean Kmart, Sears, Kohl's and other retail stores are not represented by a union.

Several retail janitors complained that they have been harassed or intimidated for trying to create a union that could address low wages and poor work conditions. A local nonprofit called the Centro de Trabajadores Unidos en la Lucha (CTUL) has been trying to organize retail workers for two years.

SEIU officials said they are working with the CTUL and other organizations to lobby corporations and retailers and contractors to increase wages.