Driven by the rising anger of their constituents, House Republicans are pushing ahead with tough legislation to tighten control of the nation's borders and clamp down on the hiring of illegal immigrants -- without offering new avenues for such immigrants to find lawful employment.

The immigration issue has opened stark divisions in the Republican Party, pitting House leaders against the White House, business groups against congressional allies, even lawmaker against lawmaker in adjoining districts.

President Bush and his handpicked Republican Party chairman, Ken Mehlman, have implored House leaders not to take up what they call an "enforcement-only" bill, arguing that such a punitive measure could jeopardize years of Republican outreach to Latinos. New enforcement measures are bound to fail unless immigrants drawn to the economic opportunities of the United States are given some chance to work here legally, they argue.

But just such a bill is barreling toward a House vote this week, Republican leaders have promised. Advocates, including the Republican leadership, say action is needed immediately to stem the flow of illegal immigrants, and such efforts should not be held up as lawmakers wrangle over the intricacies of the president's guest-worker program.

"With all due respect, this is not a political problem to be managed," said Rep. J.D. Hayworth (R-Ariz.). "This is an invasion to be stopped."

Rep. Jeff Flake (R-Ariz.), an ardent conservative who rarely disagrees with Hayworth, all but charged the congressman from his neighboring district with grandstanding, linking him to the House's anti-immigration firebrand Tom Tancredo (R-Colo.).

"Hayworth has gone Tancredo on us," said Flake, who agrees with Bush that a guest-worker program must be part of any immigration bill.

Hayworth maintained that his position -- not Flake's -- represents the views of his border state. "I have not been Tancredoed," he said. "I've been Arizonaed."

Mehlman, who has led the GOP's efforts to reach out to minority voters, tiptoed through the altercation, trying not to confront House Republicans directly. But he repeated his concern about any bill that clamped down on border security without offering an outlet for legal employment.

"There's no question you have to start at the border [with enforcement measures], but if the House bill stops at the border, you are not addressing the nation's problem of illegal immigration and homeland security," Mehlman said.

At issue is a broad bill, drafted by the House Judiciary and Homeland Security committees, that would make some of the toughest changes to immigration law in decades.

Even Latino organizations term the problem of illegal immigration a crisis. About 11 million undocumented immigrants live in the United States, often using such public services as education and health care while paying little or no taxes on under-the-table paychecks. Hayworth said illegal immigrants cost his state alone $1.6 billion a year, or $700 per Arizonan, for law enforcement, incarceration, health care, education and other public services.

And such immigrants are growing increasingly sophisticated in gaming the U.S. judicial system, overwhelming the courts, Republican aides say. The number of petitions for judicial review of deportation orders jumped from 1,654 in 2001 to 10,681 in 2004, according to the House Judiciary Committee.

Under the bill, employers would be mandated to confirm the authenticity of employees' Social Security numbers against a national database of legitimate numbers. The measure would end the "catch and release" policy for immigrants other than Mexicans who are caught entering the country illegally. All illegal immigrants apprehended at the border would have to be detained, and deportation processes would be streamlined.

Criminal penalties for smuggling immigrants would be stiffened, with new mandatory minimum sentences. Immigrant gang members would be rendered inadmissible under any circumstance. Mandatory minimum sentences would be established for immigrants who reenter illegally after deportation, and local sheriffs in the 29 counties along the Mexican border would be reimbursed for detaining illegal immigrants and turning them over to federal custody.

Many Republicans hope to go still further when the bill reaches the floor, probably Thursday. They are demanding a vote on an amendment that would end the right to automatic citizenship for any baby born on U.S. soil, and some are pushing for construction of a 2,000-mile fence on the southern border.

Latino political organizations are incensed by the bill. Cecilia Munoz, the vice president for policy at the National Council of La Raza says that the measure will overwhelm the nation's jails and law enforcement agencies without effectively stemming the flow of illegal immigrants. A parent transporting her illegal nanny to the doctor or a church housing a needy but undocumented family could be prosecuted as an immigrant trafficker.

Access to immigration courts and judicial review would be severely curtailed, and because illegal immigrants would be declared felons, their chances at naturalization would depend on never getting caught, Munoz said.

"In the spirit of trying to be tough on national security and border security, they are also conveying a real anti-immigrant sentiment," said Janet Murguia, president of La Raza.

The business lobby is not happy, either. In a letter to House Judiciary Committee Chairman F. James Sensenbrenner Jr. (R-Wis.) last week, R. Bruce Josten, executive vice president of the U.S. Chamber of Commerce, expressed disappointment that there is no temporary worker program and called the bill's mandate on employer verification impractical and unrealistic.

Business lobbyists have been able to thwart such measures before, but Republican lawmakers say the political atmosphere has changed. "When you're a majority party, you've got very differing and different constituencies," said Rep. Lincoln Diaz-Balart (R-Fla.), who expressed strong misgivings about the bill. "There is strong pressure coming from the borders on this one."

Tancredo said the pressure extends far beyond the frontier.

"If you go into a hospital in any city in America, you can't get served. Your kids are going to school, and their classes are overwhelmed. It goes on and on," he said.

The bill is moving so fast that business lobbyists have decided to let it pass and take a stand next year in the Senate. The tactic may ultimately work, but the political damage may have already been done, La Raza's Munoz said.

"For all the progress President Bush has made to reframe his party for my community, this is undermining all of that," she said. "We're not stupid."

Staff writer Jeffrey H. Birnbaum contributed to this report.

A man gathers his belongings at the border near San Diego. A House bill seeks stricter border control.