The Obama campaign is using former President Clinton to help sell its message that President Obama's policies will continue to build a "strong" middle class.

Clinton appears in Team Obama's latest ad, released on Thursday, telling voters, "The election, to me, is about which candidate is more likely to return us to full employment. 

In the ad, which will appear in eight swing states, Clinton — still seen by many as the patriarch of the Democratic Party — speaks about the energized economy during his presidency and says Obama's plan will help rebuild the middle class. 

"President Obama has a plan to rebuild America from the ground up — investing in innovation, education and job training," Clinton said. "That's what happened when I was president. We need to keep going with his plan."

Presumptive GOP presidential nominee Mitt Romney's campaign quickly released a statement that critiized Obama's policies as hurting the middle class. 

"Mitt Romney’s ‘sterling’ private-sector experience and his plan for a stronger middle class offer a new direction," said Romney campaign spokeswoman Amanda Henneberg. "He will jumpstart economic growth, creating 12 million jobs and bringing hope to the middle class.”

This isn't the first time Clinton has appeared in an ad to support Obama's policies. He appeared in a 17-minute campaign spot earlier this year to praise Obama for taking the "harder and honorable path" in his decision to OK the mission that would kill Osama bin Laden.

The former president will also appear at the Democratic National Convention in Charlotte, N.C., next month. 

This story was updated at 8:45 a.m.