Cornish Lib Dem MP Julia Goldsworthy got a dunking in the first round of Channel Four's celebrity reality show The Games.
Julia Goldsworthy will raise money for the Cornwall Air Ambulance
The accomplished rower raced through the first three gates of the kayak slalom course before she was flipped over in rapids called the Muncher.
Ms Goldsworthy, 27, is in third place among the five women in the show after the first round.
She is raising money for the Cornwall Air Ambulance.
Her participation was put in doubt after she was given a front bench job shadowing Treasury matters, as the show clashes with next week's Budget.
But the producers fitted filming around her Budget duties.
The Lib Dems' Shadow chief secretary to the Treasury will respond to Gordon Brown's Budget before being flown by helicopter to the programme's women's curling event at the Sheffield Ice Arena.
Other contestants taking part in the nine-day athletics show in Sheffield include Peter Duncan, Bernie Nolan and Michelle Gayle.