D.C. Mayor Muriel Bowser attends a news conference defending the city’s assisted suicide law from congressional interference. The law faces a new line of attack in President Trump’s budget proposal. (Matt McClain/The Washington Post)

The District would be barred from spending its own tax dollars to implement its new assisted suicide law under President Trump’s proposed budget, but a spokesman for the mayor says she is determined to implement the law anyway.

In December, Mayor Muriel E. Bowser (D) signed legislation to make the nation’s capital the seventh jurisdiction to make it legal for doctors to prescribe fatal medication to terminally ill residents.

House Republicans tried to exert congressional authority over the District earlier this year to block the measure but ran out of time before it became law. Social conservatives oppose assisted suicide because they see it as undermining the sanctity of life.

Language in the president’s proposed 2018 federal budget, released on Tuesday, would bar the city from using any funding — local or federal — to carry out the law or implement rules and regulations. The budget requires the approval of the House and Senate.

[House Republicans vow new attack against D.C. Death With Dignity Act]

(Claritza Jimenez,Dani Player/The Washington Post)

The District’s Death With Dignity Act is to take effect Oct. 1, the same day as the federal budget. It originally included a $125,000 start-up cost to create a way for doctors to document requests for life-ending drugs and for the city’s medical examiner to create methods to report such deaths.

But administration officials say they are working with the D.C. Council to use existing funds to create the monitoring and physician training systems required before October.

The mayor’s spokesman, Kevin Harris, said city officials did not believe that the proposed budget language would block the assisted suicide law once the initial costs are out of the way.

“Our understanding of the law is that it is a one-time cost, and that will already be done and underway before Congress has passed its budget,” said Harris. “The mayor made a commitment to see this through, and we are continuing to do that.”

Officials at the White House Office of Management and Budget did not immediately respond to an email seeking comment.

Regardless of the practical impact of the budget provision, Eleanor Holmes Norton, the District’s nonvoting delegate to Congress, and D.C. Council member Mary M. Cheh (D-Ward 3), who wrote the law, vowed to protect it from the latest attack.

Charmaine Manansala, national director for political advocacy with the Compassion & Choices advocacy group that helped pass the D.C. law, said her group would urge members of Congress “to respect the right of their elected officials to make public policy approved by their constituents.”

Rep. Mike Quigley (D-Ill.), the top Democrat on the appropriations subcommittee with jurisdiction over the District, said he would fight any attempt to meddle in the District’s affairs.

“When it comes to issues like who can carry a gun and where, or who can marry whom, Republicans are ardent supporters of states’ rights; but when it comes to a woman’s right to choose or assisted suicide, suddenly the decisions of local elected officials are superseded by members of Congress,” Quigley said in a statement.

The legislation was modeled after the nation’s first physician-assisted-suicide law, enacted in Oregon. It would allow doctors to prescribe fatal medication to patients believed to have less than six months to live. Patients would have to make two requests over two weeks and ingest the drugs themselves. The D.C. Council passed the measure in November by an 11 to 2 vote after more than a year of intense discussion and lobbying on the part of lawmakers, advocates and opponents.

The District is the first predominantly black community to legalize what is called “death with dignity,” overcoming objections from some African American residents and others who worried that ill patients could be coerced into an early death.

Assisted suicide is legal in California, Colorado, Montana, Oregon, Vermont and Washington state.

In 1973, Congress granted the District the right to elect a mayor and a legislative body to enact local laws but retained the right to veto the city’s legislation and spending decisions. More people live in the nation’s capital than in Vermont or Wyoming, and they pay more in federal taxes than their counterparts in 22 states. But the federal district has no voting member of Congress.