WASHINGTON —  The political ad company that Republican Mitt Romney's presidential campaign says is violating the law with phone calls in support of rival Mike Huckabee is the same firm Romney employed in August to place calls on his behalf before the Iowa straw poll.

The firm, ccAdvertising, now is working for Common Sense Issues, a nonprofit group that is financed and run by Huckabee supporters and that is conducting a pro-Huckabee campaign in Iowa.

ccAdvertising, through its Election Research division, has placed calls to thousands of Iowa voters, providing either positive information about Huckabee or negative information about his rivals.

In a letter to Iowa's Democratic attorney general, Tom Miller, the Romney campaign said the automated, interactive calls violate the federal Telephone Consumer Protection Act of 1991. The complaint says the calls do not identify the originating entity at the start of the call, do not provide a telephone number and the originating phone number does not appear on caller ID.

Patrick Davis, the executive director of Common Sense Issues, denied all the claims. He said every call begins with the script: "This is Election Research with a 60 second political survey." He said a phone number for his office is mentioned at the end of the call.

"And some phone switches in Iowa don't support caller ID," he said.

The fact that Common Sense Issues is paying for the calls is not disclosed until the end of the call.

Davis said Common Sense Issues is not coordinating with Huckabee and has not discussed the campaign with him or his staff. Huckabee, for his part, denounced the phone calls on Monday and said Tuesday that an investigation "would be fine with me."

"As you heard me say, I repudiate anything that attacks another person," he said in a press conference in Iowa. "It does not help us. I believe it hurts us."

Romney's campaign thought more highly of ccAdvertising a few months ago. It paid the firm $53,755 on Aug. 9 for survey research. The Iowa straw poll was Aug. 11. Romney won it easily; Huckabee was second.

Romney spokesman Kevin Madden said the calls that ccAdvertising placed for Romney did not present any negative information about his rivals. The calls identified people who would be participating in the straw poll, asked if they would sign up as a supporter for Romney and offered them a ride to the event, Madden said.

"It's not the vendors," Madden said, "it's the groups behind them directing the negative ad efforts against rivals with negative information as well as expressly advocating for another candidate while using (unrestricted) soft money."

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