WASHINGTON – Sen. Olympia Snowe of Maine and five other lawmakers filed papers in federal court Tuesday in defense of the new campaign finance law.

The lawmakers, in a statement, said their defense team was filing intervention papers in response to lawsuits brought by the National Rifle Association and Sen. Mitch McConnell, R-Ky., “to defend the constitutionality of all aspects of the new campaign finance law.”

The NRA and McConnell, a longtime foe of the legislation, filed lawsuits before a three-judge court in Washington just hours after President Bush signed the legislation into law March 27. They contend that the law’s restrictions on the use of money in political campaigns violate First Amendment free speech rights.

The case is expected to move quickly to the Supreme Court.

Snowe was joined by Sens. John McCain, R-Ariz., and Russ Feingold, D-Wis., the two primary sponsors of the bill in the Senate; Sen. James Jeffords, I-Vt., who with Snowe sponsored the provision in the act that is a main target of the constitutional challenge; and the two chief House sponsors of the legislation, Reps. Christopher Shays, R-Conn., and Martin Meehan, D-Mass.

The law bans corporations, unions and individuals from donating unregulated sums of “soft money” to the national political parties.

The Snowe-Jeffords language also bars the use of soft money in the final 30 days of a primary or 60 days of a general election to broadcast “issue ads” that name a candidate, usually with the purpose of attacking him.

The papers filed Tuesday state that the McCain-led group will show that “by closing loopholes in current law and prohibiting clearly identifiable abuses, the Reform Act encourages renewed citizen confidence and participation in all aspects of our democracy, thereby strengthening First Amendment values.”