Rep. Jason Chaffetz (R-Utah) in his office in Washington, D.C. on October 06, 2015. (Photo by Marvin Joseph/The Washington Post) (Marvin Joseph/The Washington Post)

Rep. Jason Chaffetz (R-Utah) said Monday he’ll use rarely invoked congressional authority to block a new law passed by the D.C. Council to allow doctors to help end the lives of terminally ill patients in the city.

Mayor Muriel E. Bowser (D) signed legislation in December that would have made the nation’s capital the seventh jurisdiction to authorize doctors to prescribe fatal drugs. The bill was transmitted Friday to Congress for a 30-day review.

[Bowser quietly signs legislation to allow terminally ill patients to end lives ]

Chaffetz, the chairman of the House Oversight and Government Reform Committee that oversees District affairs, told reporters Monday that he fundamentally disagrees with the bill.

“Assisted suicide is not something we take lightly,” he said at a news conference during which he also said he’d like to see federal agencies relocate outside the Washington region.

Supporters of medical aid-in-dying say it gives patients the option to avoid needless suffering, while opponents have raised religious objections and concerns that some may feel pressured to end their lives for financial or other reasons. Assisted suicide is legal in Oregon, Washington, Vermont, Montana, California and Colorado.

After extensive debate and public hearings, the D.C. Council voted 11 to 2 to pass the legislation in November.

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Council member Mary M. Cheh (D-Ward 3), the law’s author, said Chaffetz should not interfere.

“This is entirely a local matter and he may have philosophical or perhaps even religious objections, but we have made our own choice and it should be respected,” Cheh said. “Is he not aware there are a number of other states that have approved this? Why isn’t he using his federal powers to intervene with them? It’s only because under our degraded democracy there are some members of Congress who think they can use us a plaything.”

Peg Sandeen, executive director of the Oregon-based Death with Dignity National Center, said, “Congress has better things to do than meddle with the District’s business . . . Representative Chaffetz should stay focused on Utah.”

Bowser said through a spokesman that the District “is a self-sufficient government that pays more per capita in federal taxes than any other state in the country. We are more than capable of passing our own laws, and the best thing the federal government can do to help us continue succeeding is to leave us alone.”

Chaffetz plans to introduce a disapproval resolution by the end of January.

Congress last successfully used its power to void D.C. laws in 1991 to stop the city from changing the maximum height of buildings and in 1981 to block the repeal of a felony sodomy law. Federal lawmakers have also used appropriation powers to block the full legalization of marijuana in the city and the use of local revenue on abortions for low-income women.

[Right-to-die movement faces key test in heavily black D.C.]

Del. Eleanor Holmes Norton (D-D.C.) says if members of Congress disagree with physician-aided death, they should ban the practice nationwide. She said she intended to “fight all efforts to block the bill and to prevail.”

Chaffetz also said he would pursue efforts to have federal agencies locate operations outside the metropolitan area, an initiative he labeled “Divest D.C.”

He suggested that Congress would easily pass a measure requiring agencies to analyze the costs of operating in the District against other locations. That could save money, help local economies elsewhere and lead to a “more reflective government,” he said.

Aaron C. Davis contributed to this report.