Cambridge reaffirmed its status as a “sanctuary city” for undocumented immigrants Monday, resolving to protect residents from deportation by the federal government and to bar discrimination on the basis of immigration status.

Nearly 50 immigrants and advocates came to City Hall to express support for the resolution, which councillors passed unanimously in a roll-call vote.

The resolution was proposed in response to HR-4437, a bill sponsored by Rep. F. James Sensenbrenner Jr., R-Wisc., and passed by the House of in December.

Under the Sensenbrenner bill, anyone who helps an undocumented immigrant remain in the U.S.—“knowing or in reckless disregard of the fact that such person is an alien”—could face up to 20 years in prison. The bill would also increase the number of patrols and canine detection teams at the country’s borders.

The Cambridge resolution charges that the Sensenbrenner bill contains “counterproductive, misguided measures, including...erosion of cherished legal traditions such as due process.”

Nor does the resolution offer support for a guest worker program, such as that proposed by President Bush. The resolution says that such a program “would create a second-class citizenry without basic rights that would be disenfranchised and would be vulnerable to exploitation by unscrupulous employers.”

Gabriel Camacho, a regional organizer for the American Friends Service Committee in Cambridge, said Monday that the Sensenbrenner bill contains “proposals that mirror the language of the 1850s Fugitive Slave Act,” which made it a crime punishable by up to six months in prison to knowingly aid a runaway slave. 

Cambridge first declared itself a “sanctuary city” on April 8, 1985, when large numbers of refugees fleeing the war in El Salvador who had arrived here were denied political asylum and threatened with deportation.

—Staff writer Virginia A. Fisher can be reached at vafisher@fas.harvard.edu.