An environmental group has filed federal disclosure reports on almost $710,000 worth of advertisements lobbying lawmakers in advance of a key vote on climate change legislation. However, the Environmental Defense Action Fund is not disclosing who donated the money for the television spots.

The belated reports arrived at the Federal Election Commission three days after an article in The New York Sun noted the group’s legal obligation to file because some of the ads mentioned the speaker of the House, Nancy Pelosi, within 30 days of a primary she faced on June 3. Other ads in what the group described as a $4 million campaign to promote a so-called cap-and-trade bill ran in advance of primary elections for Senator Dole in North Carolina and Senator Pryor in Arkansas, according to the federal filings, which are supposed to be filed within 24 hours of airing a reportable ad.

“We just goofed,” a spokesman for the environmental group, Keith Gaby, said. “We’ve never in my experience done TV ads with members’ names in them, so we’re just not familiar with the territory. We found out from your question that we had to do it.”

The explanation did not mollify an official at the Club for Growth, an antitax group that mounted a smaller $250,000 TV campaign against the climate change measure.

The club’s executive director, David Keating, said his group kept its ads off the air in Montana for about a week to avoid triggering the reporting requirements that would have ensued if an ad mentioning Senator Baucus aired in advance of his primary. Mr. Keating also noted that the environmental ads lacked a disclaimer, which takes about four seconds to read and can consume an eighth of a 30-second ad.

“They’re cheating. The rest of us play by the rules even though we didn’t support the rules,” Mr. Keating said.

Under federal regulations, groups are required to identify donors who provide gifts of $1,000 or more “made for the purpose of furthering electioneering communications.” The new filings from the environmental group do not name any donors.

“It’s not an issue for us. That’s for donor directed” ads, Mr. Gaby said. “We’re a pretty well-funded group and climate is a big priority for us.”

The legislation that prompted the dueling ad campaigns failed in the Senate on June 6, when supporters got 48 votes, short of the 60 needed under Senate rules to cut off debate and bring the measure to a binding vote. Backers said they could have had as many as 54 votes, counting absent senators, still six votes short.

On May 6, Mrs. Dole defeated Pete di Lauro, 90% to 10%. Earlier this month, Ms. Pelosi defeated Shirley Golub, 89% to 11%. Mr. Pryor ran unopposed last month, but under federal political advertising rules, whether a candidate faces token opposition or none at all is immaterial.