The bill also faces objections from some labor unions, which say its temporary worker program will create an underclass of cheap laborers.

Some immigrant groups object to the bill's limits on family migration but want to see it move on to the House where they hope to get a bill more to their liking.

Josefina Sanchez, a Mexican hotel worker who has lived in the United States for 19 years and is in the process of becoming a U.S. citizen, said she was simply glad that the bill was still alive in the Senate.

"We are living in suspense, but remain hopeful," she told Reuters by telephone from a migrant welfare center in Phoenix. "It offers immigrants the hope of finally being able to live and work without fear of deportation."