Senators Kennedy and McCain joined forces yesterday to introduce a comprehensive immigration reform bill that builds upon President Bush’s proposal for a guest worker program. The bill, which was also sponsored by Representatives Jim Kolbe, Jeff Flake, and Luis Gutierrez, includes new security measures, a guest worker program, and a path to legalization for the estimated 8 to 12 million illegal immigrants in America.

“This is a comprehensive bill that doesn’t try to solve the hemorrhaging immigration problem with a Band-Aid. This bill is major surgery,” said Mr. Kolbe, a Republican from Arizona.

The bill would:

* Create a temporary worker program for unskilled workers from other countries.

* Promote working with foreign governments to provide incentives for illegal immigrants to return to their home countries.

* Enable illegal immigrants to apply for permanent legal status after paying back taxes and a fine of at least $2,000, and completing a six year temporary worker program.

* Increase border security enforcement with new technology, information sharing, and other initiatives.

* Initiate a new internal enforcement system that would place hefty fines on labor violations.

* Decrease the backlog of green card applications and promote family reunification visas.

The most controversial measure in the bill is likely to be what the authors call a “path to legalization,” in which unskilled, illegal workers could apply for legal status after paying a fine.

When Mr. Bush initially introduced his principals for immigration reform in January 2004, he included a similar path to legalization for undocumented immigrants. However, while Mr. Bush’s plan would provide a renewable three-year visa, the administration has not clarified whether his plan would lead to permanent legal status.

Under the bill introduced yesterday by Messrs. Kennedy and McCain, illegal immigrants would be able to apply for six-year temporary visas, after which they would be eligible to apply for a green card.

Mr. Kennedy, a Democrat of Massachusetts, said opponents “misleadingly categorize our efforts as an ‘amnesty.'” Legal status, he continued, “must be earned by proving past work contributions, making a substantial future work commitment, and paying monetary penalties. It is not a guarantee of citizenship, but an opportunity to continue working hard, start playing by the rules, and earn permanent residency.”

Mr. Bush met yesterday with the presidents of the Dominican Republic and five Central American countries and restated his commitment to immigration reform, White House officials said.

“The president – and the administration – is glad that this conversation on immigration is going on in Congress at this point, but we will continue to work with members from both sides of the aisle to pass a bill that meets the president’s principals,” said a White House spokeswoman, Maria Tamburri.

Senator Cornyn, a Texas Republican and chairman of the Senate Judiciary Committee’s subcommittee on immigration, will likely play a pivotal role in the debate. Responding to the legislation, Mr. Cornyn said he favors a “work-and-return” bill, not a “work-and-stay” bill, and that he will introduce his own proposal with Senator Kyl of Arizona this summer.

“I believe that legislation should be comprehensive, and should deal with four main components: border security, interior enforcement, employer accountability, and a temporary worker program,” Mr. Cornyn said in a statement. Those principals differ from the bill introduced yesterday in that they do not include a path to permanent legal residency for undocumented immigrants.

The bill’s authors stressed the measure also includes significant border and interior enforcement reforms and powerful incentives for immigrants to take temporary jobs in America and then return to their home countries.

“A realistic immigration policy must be a two-way street,” Mr. Kennedy said. “Under our plan, America will do its part, but we expect Mexico and other nations to do their part, too, to replace an illegal immigration flow with regulated legal immigration.”

Various immigrant groups, such as the National Council of La Raza, the Hebrew Immigrant Aid Society, and the American Immigration Lawyers Association, were encouraged by the move, saying they saw it as the first viable opportunity for comprehensive reform since the 1986 amnesty under President Reagan.