Citing nasty ads during the last two state Supreme Court races, five members of the state's government watchdog agency said Thursday they want to regulate thinly veiled campaign ads by requiring disclosure of who pays for them.

But the members of the Government Accountability Board acknowledged they may not have the authority to police such "issue ads," and any new rules would likely face a legal challenge.

"I think we want to do something, but ... it has to be within the parameters of the Constitution," said chairman Tom Cane.

At its meeting Thursday, the board, made up of six retired judges, didn't vote on imposing new rules on issue ads.

But it directed its staff to draft a rule that would regulate them and provide guidance as to whether it has the legal authority to adopt such a rule. The board plans to revisit the issue in October.

In a memo to the board prior to its meeting, Jonathan Becker, a board lawyer, said he believes the board does have the authority to regulate the ads and can draft rules that comply with Supreme Court decisions governing campaign finance.

Issue ads, used by business groups, unions and advocacy groups, purport to address a public policy issue and don't expressly urge a vote for or against a particular candidate. But they generally air within weeks of an election and usually mention a candidate by name.

Five board members interviewed by the State Journal on Thursday said they want to regulate the ads. The sixth could not be reached for comment.

Cane, a retired chief court of appeals judge, and other board members said the public deserves to know who funds the ads because they are viewed by the public as campaign ads.

And board members said they worry about the integrity of elections, particularly for nonpartisan judicial races, given the millions of dollars spent on issue ads during the last two Supreme Court races.

"One of the concerns you have here is, are you going to have judges elected because of their political views instead of being independent judges?" Cane said.

Gerald Nichol, a retired Dane County circuit judge, said groups that air issue ads should be accountable to the public.

Elections in Wisconsin have been "compromised" by unregulated issue ads, said Gordon Myse, a former court of appeals judge.

If the board adopts a rule requiring disclosure of the individuals, corporations and other groups that fund issue ads, it would take effect unless the Legislature overrules it.

Board members said they recognized that the Legislature might not endorse the rule and it could wind up in the courts. But they said that wouldn't deter them.

"I don't think the threat or expense of litigation should prevent us from doing the right thing, whatever that is," Myse said.

Cane said it's not likely that a new rule could be in place before the November election. But he said it's "theoretically" possible that one would be in place before the next Supreme Court election in April.