Boston - U.S. Sen. Scott Brown said Monday that a federal proposal to allow illegal immigrants a pathway to citizenship through college or military service amounts to amnesty, and claimed that supporters of the measure were "playing politics with military funding."

The Massachusetts Republican said he was upset that the so-called DREAM Act might be included in a defense bill.

"I am opposed to illegal immigration, and I am deeply disappointed that Washington politicians are playing politics with military funding in order to extend a form of amnesty to certain illegal immigrants," Brown said in a statement, while undocumented students rallied outside his Boston office in support of the measure.

A member of the Senate Armed Services Committee, Brown made the comments as Senate Majority Leader Harry Reid, D-Nev., is seeking to add the legislation to a defense bill. Some military leaders who believe it would help with recruitment support the proposal. But some Republicans oppose it and are accusing Reid of playing politics.

Under the proposal, conditional legal status would be granted to young undocumented immigrants who successfully complete high school or the equivalent. They could qualify for permanent legal residency by enrolling in college or a trade school or by joining the military within six years.

A vote on the defense bill may come as early as today.

Brown's comments come after months of pressure by student immigrant activists and various immigrant advocacy groups that wanted the senator to commit to passing a bill strongly supported by the man he replaced, the late-Sen. Edward Kennedy, a Democrat. Student activists have pushed letter writing campaigns and phone calls to Brown and staged protests and sit-ins outside his Boston office.

"He's missing the point. There are real people here," said Deivid Ribeiro, 21, an undocumented immigrant from Brazil and an aspiring astronaut. "He's the one who is playing politics by not addressing the issue. It's irresponsible of him."

On Monday, Ribeiro and a group of undocumented students launched a planned around-the-clock vigil and teach-in in front Brown's Boston office to press him on the DREAM Act.

Around 100 people from the Student Immigrant Movement and other immigrant groups marched from the Massachusetts Statehouse to the John F. Kennedy federal building, where Brown has an office, waving U.S. flags and singing songs. They arrived outside the federal building and vowed to stay until Brown announced his stance on the issue or the U.S. Senate took a vote.

"All I want is the opportunity to serve," said Carlos Savio Oliveira, 22, of Falmouth, an illegal immigrant from Brazil, who was brought to the U.S. by his parents when he was 8 years old. "I feel trapped."

Ribeiro said the group plans to hold teach-ins, as well, with volunteer professors at the protest site, reminiscent of the 1960s open forums that helped mobilize opposition to the Vietnam War.

Sen. John Kerry, D-Mass., has promised to support the legislation.

Other groups also coordinated similar protests outside lawmakers' offices in Chicago and Arizona.

In Boston, Ribeiro said students want to introduce Brown, a member of the Army National Guard, to Oliveira, who said he would join the U.S. Navy if the proposal passed.

"For me, the Navy would only be the beginning," said Oliveira, who left for Washington, D.C., after Monday's event to lobby other lawmakers. "The military would be a stepping stone in my life."

The same student immigrant advocates held an around-the-clock vigil this summer outside the Statehouse to protest a state budget amendment aimed at cracking down on illegal immigrants. The amendment later was defeated, inspiring a coalition of student immigrant advocacy groups in Massachusetts, Colorado and California to launch Dream University.