Voters in at least 10 swing states are receiving hundreds of thousands of automated telephone calls  uniformly negative and sometimes misleading  that the Republican Party and the McCain campaign are financing this week as they struggle to keep more states from drifting into the Democratic column.

Senator John McCain, the Republican nominee for president, has denounced such phone calls in the past: In the 2000 primaries, Mr. McCain was a target of misleading calls that included innuendo about his family, and he blamed them in part for his loss to George W. Bush. This January, too, in South Carolina, Mr. McCain described the calls against him as “scurrilous stuff,” and his campaign set up a “truth squad” to debunk them.

On Friday, a Democratic official in Minnesota said he had received one of these so-called robocalls and had tracked it to a company owned by a prominent Republican consultant, Jeff Larson. According to published news reports, Mr. Larson and his previous firm helped develop the phone calls in 2000 that took aim at Mr. McCain.

A spokesman for the McCain campaign could not say Friday night whether it had contracted with Mr. Larson’s current company, FLS Connect. Phone messages left for Mr. Larson were not answered Friday, nor were messages left at a subcontractor, King TeleServices, which is making the actual calls to voters in Minnesota.