Massachusetts, which advocates for “sanctuary cities,” the controversial policy instructing local police officers not to cooperate with federal immigration enforcement agents, may soon push for a statewide shielding of undocumented immigrants. Emboldened by a handful of existing sanctuary cities, at least two dozen state lawmakers have backed a proposal that would make the commonwealth a safe haven for undocumented people who fear deportation if they interact with local law enforcement, the Eagle Tribune newspaper reported Thursday.

The proposal is also backed by immigrant rights groups, but faces bipartisan opposition in Massachusetts and around the U.S. Immigration emerged as a top political issue in the upcoming presidential election, in which Republican candidates have blamed sanctuary cities for contributing to crime and to the size of the undocumented population, which has been estimated at 11 million nationwide.

Six Massachusetts communities, including Boston, Somerville, Cambridge, Amherst, Northampton and Lawrence, have told their police to not hold undocumented immigrants for deportation without a warrant from the federal Immigration and Customs Enforcement agency. There are no Republican supporters of the statewide proposal, and several Democratic opponents said they were not on board, out of concern that the measure would jeopardize state and national security.

"To me this is clearly an attempt to undermine federal law," said state Rep. Linda Campbell, a Democrat from Methuen, Massachusetts, according to the Eagle Tribune report. "I think it would set a dangerous precedent, and the repercussions would affect all of us."

Campbell and other Democrats who oppose becoming a “sanctuary state” said the issue highlights the need for comprehensive federal immigration reform, which stalled for years in the U.S. Congress. Meanwhile, President Barack Obama has offered to extend deportation deferrals to more than five million young undocumented immigrants and their parents last year. The plan has been on hold while a panel of federal judges deliberates on a legal challenge to Obama's policy brought by 24 Republican-led states.

California, New York, Rhode Island, Connecticut and at least 340 communities nationwide have taken steps similar to the one proposed in Massachusetts. In 2014, the Pew Research Center estimated that there were 150,000 undocumented immigrants -- 2.3 percent of the state’s 6.7 million residents -- living in Massachusetts.

More than half of the immigrants deported from Massachusetts under ICE's local law enforcement partnership have no criminal background, said Eva Millona, director of the Massachusetts Immigrant and Refugee Advocacy Coalition. She said “sanctuaries” improve the relationship between police and immigrant communities, which have been known to underreport crimes for fear of being detained and deported.

Proponents of a statewide shield, dubbed the “Trust Act,” said it won’t interfere with local police departments’ effort to fight crime. Republican Gov. Charlie Baker has already threatened to veto sanctuary legislation if it reaches his desk, according to the Eagle Tribune.

"I personally think this kind of a law sends the wrong message," said state Rep. Brad Hill, a Republican from Ipswich, Massachusetts, who also opposes the measure. "If any city or town breaks federal law…there should be penalties."