Lachey (left) and Simpson Photo by: tsuni / gamma

Jessica Simpson has been tapped as cohost of the Teen Choice Awards, and she may have her work cut out for her at the Aug. 20 event. Not only is she a nominee, but so is her ex-husband, Nick Lachey, and his new squeeze, Vanessa Minnillo.

Simpson is nominated for choice movie breakout performance – for her role as Daisy Duke in The Dukes of Hazzard – as well as for choice red-carpet fashion icon and choice hottie. Meanwhile, Lachey is nominated in the male hottie category and Minnillo is up for choice TV personality.

Simpson and Lachey, who costarred in the MTV reality show Newlyweds: Nick & Jessica, finalized their divorce on June 30 after three years of marriage. Recently, Lachey has been spotted spending time with Minnillo in New York and Los Angeles.

The eighth annual Teen Choice Awards, during which winners will be presented with surfboard awards, will air live on FOX (at 8 p.m. ET). Simpson's cohost will be announced at a later date, the network said Tuesday.

Voters can cast their ballots until Aug. 11 on the Web sites TeenPeople.com, MySpace.com, Ign.com and Fox.com.

Up next for Simpson, 26, is a starring role in the comedy Employee of the Month, which opens Sept. 15. Her new album, A Public Affair, hits stores Aug. 29.

Lachey, 32, is scheduled to kick off his "What's Left of Me" tour on Sept. 20 in Albany, N.Y.