Orrin Hatch said Monday that he'll need more time to dig through the 1,000-page immigration bill introduced in the Senate before he can make an informed decision.

"I need to look at it carefully, talk to Utahns, and get their views on this complex proposal before deciding whether to oppose or support it," he said.

The Utah senator and others are getting that wish.

Senate leaders on Monday gave themselves an extension until June on what President Bush and lawmakers in both parties say is one of their most important assignments for the year: a broad immigration overhaul.

The reprieve gives the Senate more time for what promises to be a volatile debate on a bipartisan compromise that would give an estimated 12 million unlawful immigrants legal status.

The issue carries heavy political consequences for both parties. It's a top priority for Bush, who considers it a defining element of his legacy, and for congressional Democrats who are eager to count it as one of their accomplishments at the helm of Congress.

The measure, which also tightens border security and workplace enforcement measures, unites a group of influential Senate liberals, centrists and conservatives, but it has drawn criticism from across the political spectrum.

For example, presidential candidate Mitt Romney leveled sharp criticism at the bill saying that, "Any legislation that allows illegal immigrants to stay in the country indefinitely, as the new 'Z-Visa' does, is a form of amnesty."

The Z-Visa is a form of temporary work visa.

The unlikely coalition that brokered the deal, led by Sens. Edward M. Kennedy, D-Mass., and Jon Kyl, R-Ariz., is plotting to protect the agreement from "deal-breaker" changes that would sap its support. The group will hold daily meetings starting Tuesday to determine whether proposed revisions would sink what they are calling their "grand bargain."

Emily Chirstensen, spokeswoman for Sen. Bob Bennett, R-Utah, said that the senator will continue to review the legislation as it develops; however, "given general principals, he hopes to support it in the end."

How the bill will affect Utah County residents is still mostly unknown; however, business owners rely heavily on workers from other countries.

"Utah County would collapse without migrant workers," said Provo-Orem Chamber of Commerce President Steve Densley.

Densley said that between construction, manufacturing and farm work, Utah County businesses depend heavily on migrant workers.

Densley said that for the most part, businesses in the county believe their workers are legal, and pay taxes on them as if they were legal. He said all employers are expected to research and check the legal status of their employees within reason. As such, he wasn't sure how illegal immigrants gaining a legal status would affect local business' bottom line.

Utah reports April unemployment at 2.5 percent, 2 percent lower than the national rate.

Gabriel Perez of the Hispanic Chamber of Commerce said that he isn't sure how the immigrant community will respond to the legislation; however, he agreed with Densley that Hispanic workers have a critical role in the community.

Conservative critics denounced the proposal's quick granting of legal status to millions of unlawful immigrants.

Sen. Jeff Sessions, R-Ala., said the measure's so-called "point system" doesn't do enough to guarantee that future immigration will serve the country's economic needs.

"I'm nervous about this thing," said Sessions, who voted not to go forward with the debate. He called the point scheme "bait" to get conservatives to embrace the measure, and accused Republicans of compromising too much on an outline drafted by the White House in late March to attract GOP support.

"I'm disappointed -- almost heartbroken -- because we made some progress toward getting to this new framework, but the political wheeling and dealing and compromising and splitting the baby has resulted in a circumstance that, you know, we just didn't get far enough," Sessions said.

Sen. Kay Bailey Hutchison, R-Texas, who also opposed opening debate, announced she would seek to alter the bill to mandate that illegal immigrants go back to their home countries before gaining legal status.

Kennedy called the plan "strong, realistic and fair."

"For each of us who crafted it, there are elements that we strongly support and elements we believe could be improved. No one believes this is a perfect bill," Kennedy said.

The White House has begun an active lobbying effort to drum up support for the measure, especially among Republicans who voted against an immigration overhaul last year.

Bush is still hoping to sign the bill by summer's end, said Tony Fratto, a White House spokesman.

Conservatives in the House, whose opposition helped kill an immigration overhaul last year, began laying down markers in anticipation of their own debate, expected only if the Senate completes its measure.

Rep. Dan Lungren, R-Calif., unveiled legislation he said was "an alternative to several of the large holes in the so-called Senate compromise."

It would send home illegal immigrants who had been in the U.S. for fewer than five years and bar them from gaining lawful status.

Those in the country five years or more would be able to get a "blue card" to live and work legally in the U.S. after paying a $1,000 fine and learning English and American civics, but they could not bring their families. Blue card holders would have to leave the country to apply for legal residency.

In contrast, the bipartisan Senate compromise would allow illegal immigrants in the country by the beginning of this year to adjust their status.

Daily Herald reporter Nathan Johnson contributed to this story.

This story appeared in The Daily Herald on page A1.