Facing a court deadline, the Federal Election Commission reaffirmed its decision not to issue regulations telling free-spending political groups known as 527s precisely what actions would subject them to contribution limits and other restrictions.

On Wednesday, the commission voted, 4–2, to issue a new statement of “explanation and justification” for its policy favoring case-by-case adjudication over detailed regulations.

Under a long-standing Supreme Court decision, federal limits apply only to groups that have the “major purpose” of influencing federal elections.

“The Commission’s decision not to establish a political committee definition singling out 527 organizations is informed by the statutory scheme, Supreme Court precedent, and Congressional action regarding 527 organizations,” the federal election regulators wrote in their new 44-page statement. The commission said it “requires the flexibility of a case-by-case analysis of an organization’s conduct that is incompatible with a

one-size-fits-all rule.” The panel also said 527 status, which is derived from the tax code, is irrelevant to whether a group should be regulated by the commission.

In 2004, two congressmen who support stricter campaign finance regulation, Christopher Shays of Connecticut and Martin Meehan of Massachusetts, filed suit against the commission, demanding that it impose controls on 527 committees. A federal judge, Emmet Sullivan, declined to order the commission to issue rules, but said the panel was obliged to explain more fully its rationale for not doing so.

One of the two commissioners who dissented from the new explanation, Hans von Spakovsky, said the panel’s failure to issue clear rules is chilling the activities of advocacy groups. “I think that does a disservice to all kinds of organizations, not just 527s, but 501c4s and others,” he told The New York Sun. “The worst situation you can have is when you don’t have a law or regulation that lays out what’s legal and what’s not.”

President Bush is among those who have urged the government to rein in the independent 527 groups, which spent about half a billion dollars at the federal level in 2004 and more than $200 million in 2006. The groups are attracting many of the same donors who gave large sums of so-called soft money to the political parties before that practice was banned by legislation passed in 2002.

In December 2006, the commission announced that several prominent 527s agreed to pay fines for failing to register and report on their involvement in federal elections. Swift Boat Veterans and POWs for Truth paid nearly $300,000, the League of Conservation Voters paid $180,000, and MoveOn.org paid $150,000. A conservative group, Club for Growth, is fighting a similar enforcement effort in federal court.

Groups at both ends of the political spectrum have expressed concern that tighter regulations could affect charities and issue advocacy groups that have never been required to disclose donor lists or limit donations.