A New York congresswoman’s proposal to have the federal government regulate advertising for abortion counseling services has won the support of the American Civil Liberties Union, despite warnings from other civil libertarians that the measure is unconstitutional and unwise.

Rep. Carolyn Maloney, a Democrat who represents parts of Manhattan and Queens, introduced legislation yesterday aimed at cracking down on so-called crisis pregnancy centers, which are operated by anti-abortion groups and encourage pregnant women to consider other options.

“It seems to me they’re purposely trying to confuse people,” Ms. Maloney told The New York Sun. “If you’re a pro-life group, put out a banner that says, ‘pro-life counseling.'”

Ms. Maloney said the counseling centers draw women in by using names and signs that are intended to cause confusion with Planned Parenthood and other abortion providers. “The centers do not provide abortion services. They only offer anti-choice coercion,” she said. “Women I’ve talked to are just unbelievably shaken by it. One said they closed the door and wouldn’t let her get out.”

Ms. Maloney’s bill would require the Federal Trade Commission to adopt rules to prohibit any person from advertising “with the intent to deceptively create the impression that such person is a provider of abortion services if such person does not provide abortion services.” The legislation defines “abortion services” to include drugs and surgery to terminate a pregnancy, as well as referrals for such services.

Ms. Maloney said the bill was crafted to avoid infringing on free speech. “We’re very careful and worked with the ACLU so that the ACLU has endorsed it,” she said.

The director of the Washington legislative office of the ACLU, Caroline Fredrickson, joined Ms. Maloney at a press conference yesterday announcing the legislation.

Ms. Fredrickson said the Federal Trade Commission should have addressed the pregnancy centers’ conduct under existing law, but has not. “It’s already clear that deceptive advertising and false advertising is illegal,” the ACLU attorney said.

A law professor who specializes in First Amendment issues, Eugene Volokh, said he was surprised by the ACLU’s stance in favor of the bill. “It’s pretty striking to see the ACLU, which stands for very, very broad free speech protection, actually backing a new speech restriction,” the professor said. “Proposing a new restriction on misleading, non-commercial speech is a big step.”

Mr. Volokh, who teaches at the University of California, said some aspects of the bill were probably constitutional, but others were not likely to pass muster in the courts. Ads from centers falsely claiming to offer abortions for a fee could likely be banned, he said, but any attempt to regulate ads for free abortion counseling or referrals would be on shaky ground. “What is a referral? A referral is speech,” the professor said. “You might say it’s unethical to try to lure people in this way, but it’s not commercial speech.”

Mr. Volokh said one problem with the law is that it attempts to regulate speech that is arguably misleading or deceptive, but not necessarily false. “The same logic would justify regulating a broad range of political or historical statements,” he said. “I think that’s a pretty dangerous policy.”

Told of the ACLU’s stance on the bill, a former member of the organization’s board, Nat Hentoff, exclaimed, “My God, what about the First Amendment?”

Mr. Hentoff, who is anti-abortion, said the Federal Trade Commission should not wade into the perilous waters of the abortion debate. “When you have the state, with its power, deciding what is deceptive on something as thoroughly controversial as this, it goes against the very core, it seems to me, of the First Amendment,” he said.

Mr. Hentoff, who called ACLU’s endorsement of the legislation “a really extraordinary mistake,” said the organization has become so protective of abortion rights that it has lost sight of free speech issues. “It’s the problem the ACLU has had for years,” he said.

Asked about claims that the legislation would infringe on free speech, Ms. Fredrickson said, “We differ. When an entity says it provides abortion services or family planning and so forth, I think it is squarely an issue when the women are then told why they should have neither of those things.”

Both Ms. Maloney and Ms. Fredrickson said they would consider an anti-abortion group advertising “abortion counseling” to be acting deceptively. “When they say free abortion counseling, it makes it sound like Planned Parenthood,” Ms. Maloney said. She said anyone falsely claiming to offer treatment for Parkinson’s Disease or cancer would have been shut down long ago by health authorities.

Two constitutional scholars contacted by the Sun, Erwin Chemerinsky of Duke University and Burt Neuborne of New York University, said they thought the bill was constitutional. However, Mr. Neuborne, said he feared the legislation could cause more problems than its authors realize. “I would counsel against it. It’s just not a good idea,” he said. “When the government regulates speech, it screws it up.”

A Boston attorney active in the ACLU, Harvey Silverglate, said he feared how the Bush Administration might enforce such a rule. “It is just as easy to have a government hostile to abortion as it is to have a government truly interested in keeping it legal and keeping it safe,” he said.

Some familiar with the ACLU’s operation said the staff has long been split between a faction that favors free speech concerns and another that is more concerned with protecting women’s access to abortion. In 1992, some attorneys who advocated abortion rights quit the ACLU and founded a spin-off group, now known as the Center for Reproductive Rights.

In New York, there have been a series of investigations of allegations of false advertising by crisis pregnancy centers. In 2002, one counseling center, Birthright, in upstate Victor, agreed with the state to make clear to women that the center does not offer medical services, abortion or abortion referrals.

A spokeswoman for a national network of more than 2000 anti-abortion counseling centers, CareNet, said her group views the legislation as unnecessary, but does not oppose it. “No matter how opposed we are to abortion, we are for women and want to be up front in all advertising that we do not offer abortion services,” the spokeswoman, Kristin Hansen, said.