For months media consultants have been grousing about the new “Stand By Your Ad” requirement for televised campaign commercials, arguing that it eats up precious moments in the already tight 30-second ad.

Now some radio networks are chiming in with criticism of the new political advertising requirement.

Metro Networks Communications Inc. — a national company that provides more than 2,000 radio stations across the country with live traffic, news, sports and weather reports — has asked the Federal Election Commission for an exemption from the requirement, arguing that it would be “physically impossible” for the company to comply with the provision.

Tom Fanning, national director of marketing for Metro Networks, explained in a letter to the FEC that his company’s reporters give live reports in real time on any variety of topics, and read a 10-second sponsorship message at the end of their report.

For instance, a reporter might read a sponsor’s statement that says: “Candidate ABC has waged war on terrorists who want to take away America’s liberties. But the job is not done. Support Candidate ABC for re-election. Paid for by the committee to re-elect candidate ABC.”

However, under the Bipartisan Campaign Reform Act, candidates are required to identify themselves as the messenger of their ads.

Radio ads must include “an audio statement by the candidate that identifies the candidate and states that the candidate has approved the communication.” Television ads must do the same as radio ads, but must also include a full-screen unobstructed view of the candidate making the statement and at least four seconds of writing on-screen also stating he or she approved the ads.

“Candidates have expressed interest in buying our sponsorships to reach out to the American public, but feel that this regulation prevents them from purchasing our sponsorships,” Fanning wrote.

In theory, the new requirements were intended to cut down on the proliferation of negative ads, with lawmakers reasoning that if candidates had to claim ownership of their ads, they might be less inclined to launch spurious attacks on their opponents.

But Fanning, who is based in Silver Spring, Md., says that because of the limitations of his company’s equipment, it would be physically impossible to attach prerecorded disclaimers from candidates to the 10-second promotional statements that are read by on-air reporters when those candidates sponsor the news.

“Metro Networks can comply with the ‘stand-by-your-ad’ requirement if the commission allows our reporters to read it live within our opening mention or in the sponsorship message,” Fanning said. “The ‘stand-by-your-ad’ requirement, as it stands now, effectively prevents candidates from accessing this method of reaching voters with important information.”

The FEC will answer Metro Networks’ concerns through the issuing of an advisory opinion in coming weeks.