A bill to ban abortions in the District after 20 weeks of pregnancy took a key step forward Wednesday as a House committee approved the controversial measure along party lines.

The measure, sponsored by Rep. Trent Franks (Ariz.) and supported by his fellow Republicans on the House Judiciary Committee, would ban all abortions in the District after 20 weeks except to save the life of the mother, under the theory that fetuses can feel pain beyond that point. Panel Democrats opposed the bill, calling it an assault on abortion rights and on the District’s ability to make its own laws.

D.C. officials view the bill as the latest affront to the city from the Republican-controlled House. Franks, who has been the target of protests by D.C. activists, made little mention of the District or the debate over home rule during the hearing, instead focusing on the broader abortion issue.

“We are talking about a bill to protect children from being torturously dismembered while they are capable of feeling pain,” he said.

Del. Eleanor Holmes Norton (D) complained after the vote that the District was being treated as a pawn. “We are not puppets to be used by the right-to-life forces, who are parading this same bill through the states to work up a head of steam against Roe v. Wade,” Norton said.

The bill would likely command majority support if it comes to a House floor vote, though its ultimate fate is unclear. It is unlikely to come up for stand-alone consideration in the Democratic-controlled Senate. But Senate Republicans could seek to attach it to other legislation.

At a controversial May subcommittee hearing on the bill, Republicans brought forth medical experts to testify that fetuses can experience pain beyond 20 weeks. On Wednesday, Franks asserted that the scientific consensus that such pain occurs “is almost universal,” but the medical community is actually quite divided on the question.

The May hearing also drew attention for an omission from the witness list: Norton, who sat silently in the front row of the audience after her request to speak was denied by Republicans.

No witnesses appeared at Wednesday’s markup. But Norton had a statement inserted into the committee record arguing that the legislation “is unprincipled twice over. As to the District, it is the first bill ever introduced in Congress that would deny constitutional rights to the citizens of only one jurisdiction in our country. It is also the first bill ever introduced in Congress that would ban abortions after 20 weeks of pregnancy.”

The bill, which has more than 200 co-sponsors, is a top priority of the National Right to Life Committee.

“A vote against this bill amounts to a vote to ratify the extreme policy currently in effect in the nation’s capital, where abortion is completely legal for any reason until the moment of birth,” said Douglas Johnson, the organization’s legislative director. “Under the Constitution, members of Congress, and the president, are ultimately accountable for this extreme policy.”

Abortion rights advocates say the bill clearly conflicts with the Supreme Court’s Roe v. Wade decision. Rep. John Conyers Jr. (Mich.), the Judiciary panel’s top Democrat, called it “arrogantly unconstitutional.”

“I don’t think a member would ever dream of overriding the rights of citizens in any other city in America,” Conyers said. “It takes advantage of the fact that citizens of the District lack equal representation of Congress.”

Also Wednesday, the two sides sparred over a provision of the bill allowing a current or former medical provider of a woman seeking a post-20-week abortion to go to court to seek an injunction against the procedure. Democrats tried without success to amend that portion of the bill.

The District has the fewest restrictions on late-term abortion in the region, a fact that has not escaped the attention of Congress. In a letter to colleagues last month seeking support for the fetal pain bill, Rep. Christopher H. Smith (R-N.J.), a leading abortion opponent, said that “current District policy is utterly indefensible.”

Maryland and Virginia prohibit abortions after a fetus is considered viable, a determination that is made by a doctor.

Late-term procedures account for a very small percentage of all abortions nationwide each year, according to government statistics, but there are no reliable data on exactly how often such abortions are performed in the District.