The pair - who fronted the BBC show What Not To Wear for five years - are said to be travelling to Australia next month to enter the jungle.
"It will be great watching Trinny and Susannah trying to slum it in the jungle," a source told The Sun.
"They are both strong and opinionated women and they're bound to ruffle a lot of feathers."
When asked about the presenters' dedication to style, the source added: "They'll have to wear the same T-shirts and shorts as everyone else."
Woodall and Constantine are thought to have joined this year's lineup because they are keen to relaunch their showbiz careers. After leaving the BBC, they moved to ITV in a deal worth a reported £1.2 million and went on produce two series of Trinny and Susannah Undress.
Following their exit from TV in 2007, Woodall and Constantine have taken on much smaller projects, which have included promoting their own fashion range on shopping channel QVC and launching their own brand of slimming knickers.
"Trinny and Susannah have enough money not to work but they miss the buzz of telly," the source explained. "They want to get back on prime time and back into proper fashion."
A number of London 2012 Olympic stars are rumoured to be joining Woodall and Constantine in the jungle. Producers working on the 12th series of the show are said to have set their sights on swimmer Rebecca Adlington and gold medal-winning cyclist Bradley Wiggins.
