A Wisconsin anti-abortion group filed a lawsuit Wednesday challenging the federal campaign finance law's restrictions on advertising in the months leading up to an election.

The law prohibits interest groups from running corporate-funded radio and TV advertisements that mention a candidate's name within 30 days of a primary or 60 days of a general election. Wisconsin Right to Life (search) claims that unfairly restricts its free-speech rights.

The anti-abortion group wants to run commercials asking people to call Wisconsin Sens. Russ Feingold (search) and Herb Kohl (search), both Democrats, urging them to oppose filibusters of President Bush's judicial nominees. But because Feingold is running for re-election this year, the group is barred from mentioning his name.

Even though the Supreme Court has upheld the 2002 law, which was co-sponsored by Feingold, Wisconsin Right to Life argues that it can win this case because it involves a real-life challenge, not an abstract ruling on the statute's constitutionality.

The group asked the U.S. District Court for the District of Columbia to issue a preliminary injunction banning the Federal Election Commission (search) from enforcing this provision.

Wisconsin Right to Life argues that the ads don't constitute "electioneering," which the law was meant to regulate. Instead, the group said, the ads "constitute bona fide grass-roots lobbying."

Such lobbying by definition must mention a candidate by name, the group argued.

"Grass-roots lobbying is impossible without telling constituents to whom their call should be made," Wisconsin Right to Life said in the lawsuit filed by attorney James Bopp, who was one of the lawyers who unsuccessfully challenged the law before the Supreme Court in 2003.

Wisconsin Right to Life has endorsed three of Feingold's potential Republican opponents — Russ Darrow, Tim Michels and Bob Welch.

An FEC spokesman declined to comment on the suit.

Floyd Abrams, a First Amendment lawyer who had challenged the law before the Supreme Court, said Wisconsin Right to Life faces an uphill battle.

"Obviously, the government would argue it's already been decided," said Abrams, who is not involved in this case. "But by focusing on a particular ad in a particular place, there's at least a possibility that the courts might say that we didn't really mean there were no cases in which the 30- and 60-day provision was immune from challenge."

Larry Noble, executive director of the Center for Responsive Politics, a campaign finance watchdog group, said the suit had very little chance of succeeding.

"The Supreme Court has already ruled on it," said Noble, former general counsel to the FEC. "The Supreme Court ruled on a challenge that the electioneering communication was over-broad, and the Supreme Court said it wasn't. This seems to be a direct challenge to what the Supreme Court has already said."