Labor unions such as the United Farm Workers, the United Food and Commercial Workers, the Teamsters and others are seeking to organize growers and others in the newly legal pot industry in states such as California.

Tens of thousands of people are involved in the industry, which has unions seeking to outmaneuver each other in an effort to sign them up.

"If you're a cannabis worker, the UFW wants to talk with you," national Vice President Armando Elenes told the Associated Press.

California will have legalized the sale of recreational marijuana to people 21 years and older starting Jan. 1. The industry is expected to quickly grow as the state's existing medical marijuana industry is already bringing $22 billion a year. Union leaders predict as many as 100,000 workers are potentially available to be organized in the labor-friendly state.

That effort could be complicated by unions competing for those members, which could create tension within the otherwise mellow industry. "We would hope they respect our jurisdiction," UFCW spokesman Jeff Ferro said.