George H.W. Bush disapproves of his cameo in Michelle Nunn ad

Georgia's Democratic Senate candidate Michelle Nunn has released a new ad highlighting her relationship with former President George H.W. Bush, but the former Republican president doesn't appreciate the attention.

In the ad, Nunn is pictured with President Obama and Mr. Bush at an event honoring the former president. Nunn notes that she previously served as CEO of Mr. Bush's Points of Light foundation.

"Throughout my career I've been able to work with Republican and Democrats," she says.

However, Mr. Bush's spokesman Jim McGrath confirmed to CBS News that the former president does not want to be involved in the Democrat's campaign. Mr. Bush is supporting Nunn's opponent, Republican David Perdue.

"Michelle and her team have been clearly, repeatedly and consistently told that President Bush did not want them to use his photo as part of this campaign," McGrath said in a statement. "Apparently, the Nunn team feels they can repeatedly disregard the former president's wishes, which is very disappointing because it's so disrespectful."

Nunn is putting up a surprisingly strong challenge against Perdue in the open race to replace retiring Republican Sen. Saxby Chambliss. A poll released last month by the Atlanta Journal Constitution shows Republican David Perdue garnering 45 percent, while Democrat Michelle Nunn wins 41 percent and Libertarian Amanda Swafford takes 6 percent.

The race could go to a runoff, should no candidate garner more than 50 percent of the vote on Election Day on Nov. 4. A potential runoff election would take place on January 6 -- one day after the new Congress is set to convene.