DES MOINES, Iowa — Former Vice President Al Gore will headline the Iowa Democratic Party’s annual Jefferson-Jackson Day dinner in Des Moines.

The dinner is the party’s biggest annual bash and traditionally opens the sprint through the final weeks to the general election.

Gore, who won the state’s leadoff precinct caucuses in 2000, has emerged as an environmental leader and won the Nobel Peace Prize in 2007 for his work on climate change. He will keynote the dinner on Oct. 4.

Iowa Democratic Party Chairman Scott Brennan scheduled a news conference Tuesday to announce the event, but the party posted a notice on its Web site with a schedule for the dinner.

The Jefferson-Jackson Day dinner is used to give activists a jolt of energy heading into the closing days of a campaign. The keynote invitation is a hotly contested prize.