Business groups say they still support comprehensive immigration reform, but they question whether now is the right time to take up such controversial legislation.

Senate Democrats unveiled a 26-page “conceptual proposal” for immigration reform April 29 and invited Republicans to work with them on turning the outline into legislation. The proposal calls for beefing up security on America’s borders and then providing a process for illegal immigrants who already are here to gain legal status if they register with the federal government, pay back taxes, learn English, and stay out of trouble.

“What we have in mind is not amnesty,” said Senator Dianne Feinstein, a Democrat from California. “It’s a tough and fair path forward for those who have contributed to American society.”

For businesses, the key provisions are new requirements for ensuring that they don’t hire undocumented workers and programs that would allow them to hire temporary workers from other countries if they can’t find Americans to fill jobs.

Democrats contend immigration reform is long overdue and has become a more urgent priority as the result of a new Arizona law that directs police to ask for documentation from anyone suspected of being in the U.S. illegally. That law will lead to racial profiling, Democrats said.

Republicans, however, are unlikely to accept Democrats’ invitation to work together. Senator Lindsey Graham of South Carolina, who until recently was engaged in talks with Democrats on immigration reform, dismissed the Democratic proposal. A joint statement issued by Graham and his GOP Senate colleague Jon Kyl of Arizona, said the proposal “is nothing more than an attempt to score political points. It poisons the well for those of us who are working toward a more secure border and responsible, bipartisan reform of our immigration laws.”

Business groups expressed mixed feelings about the Democratic proposal, particularly its timing.

“I think it helps push the negotiations forward, but I don’t think it will result in a bill that will go to the floor this year,” said Randel Johnson, the U.S. Chamber of Commerce’s senior vice president for immigration policy. “There’s no way the votes are going to be there this year.”

An immigration bill that fails would only make it harder to deal with the issue next year, he said.