At the beginning of what promises to be an extended congressional debate about the country’s immigration policies, Rep. Peter King, a Republican of New York, yesterday tied the discussion to New York City.

When he was growing up in one of the city’s immigrant neighborhoods, all types of people were welcomed, Mr. King said, but “September 11 brought home to us dramatically the terrorist aspects of illegal immigration.”

Now, he said, the key to securing America’s borders and halting the flow of illegal immigrants lies in a bill he crafted with the chairman of the Judiciary Committee, Rep. James Sensenbrenner, a Republican of Wisconsin. If only everyone in his party agreed with him.

Contention is rife among House Republicans over the immigration bill, which includes enforcement measures, such as having employers verify the status of their workers, but not a guest worker program, which is favored by President Bush.

The House yesterday voted 220-206 to approve a parliamentary measure needed to move ahead on the bill, the Associated Press reported, but only after Republican leaders appealed in a private meeting for party unity.

Some opponents, led by Rep. Tom Tancredo’s 92-member immigration reform caucus, insisted it should include scores of additional amendments, including revoking citizenship for children born to illegal immigrants in America. Mr. Tancredo is a Republican of Colorado.

Critics on the other side of the debate also said the bill does not go far enough – because it does not address the 11 million illegal immigrants already in the country by putting in place some type of work visa program.

“There’s kind of a left-right coalition against it,” Rep. Jeff Flake, a Republican of Arizona, told the AP. Mr. Flake and Rep. Jim Kolbe, also a Republican of Arizona, have introduced a comprehensive immigration bill that includes a guest worker program and is backed by the U.S. Chamber of Commerce, as well as many other business groups. They said that unless illegal immigrants in this country are dealt with, there is no reform.

Democrats loudly opposed the Sensenbrenner-King bill, saying comprehensive reform is needed and that measures to make immigration violations criminal are wrong. “The Republicans proposing this bill would have the American public believe that this measure will increase border security and keep out terrorists. But unfortunately the opposite is true,” Rep. Jose Serrano, a Democrat of the Bronx, said in a statement. “By criminalizing immigration, it drives those interested in immigrating further into the shadows, where they are preyed upon by unscrupulous traffickers. At the same time terrorists seeking entry could utilize these same illegal networks to gain safe passage across the border.”

The legislation would make it a federal misdemeanor to be caught living illegally in America, not just a violation of civil immigration law. Employers would be required to verify the immigration status of their employees. The “catch-and-release” policy for non-Mexicans, under which they are freed when caught at the border, would be ended. The Pentagon and the Department of Homeland Security would create a coordinated military technology plan to protect the border.

“The bill really is extreme. It goes very far,” the deputy director of the pro-immigrant National Immigration Forum, Angela Kelley, said. “It’s likely the bill will go through, but it’s not going to be the slam-dunk vote the leadership thought they were going to have.”

The divide uncovered during the House debate, a senior fellow with the Manhattan Institute, Tamar Jacoby, said, shows how challenging finding a solution to immigration reform will be. “What it exposed, in a way that is troubling, is how difficult it is going to be to thread this needle, to come up with something that is going to work for the different sides,” Ms. Jacoby said. “It is going to take a very delicate and carefully crafted compromise.”

In the Senate, where immigration legislation is expected to be considered on the floor early next year, compromise is more likely, she said. Yesterday, Senators Obama and Martinez came out in support of a compromise between two Senate immigration reform bills that include guest worker programs.

“Some of the proposed ideas in the House that’s being debated today and tomorrow call for only increased enforcement of the borders and at the workplace,” Mr. Obama said yesterday. “If the policy we end up with tells these immigrants that they will never be good enough to become Americans, then the policy will not work.”

The House is likely to complete consideration of the immigration bill Friday.