The politician faced rugby star Gareth Thomas in the Save Me Skate, which was one of the most dramatic in the reality show's history after King's partner suffered a severe injury live on air.
After discovering they had to perform again, 45-year-old Baroness King and professional partner Mark Henretty were skating out onto the ice when Henretty fell.
He appeared to clutch his arm in pain and had to be sent away to receive medical attention.
It was revealed by presenter Phillip Schofield that Henretty had suffered a dislocated shoulder live on air, and the performance was suddenly in doubt.
However, after having the joint popped back in, Labour politician King and Henretty performed their skate to 'Just the Two of Us'.
Henretty said of the accident: "It popped out, but they popped it back in. I'm fine, I'm good. it's back in now."
Judges Robin Cousins, Karen Barber and Jason Gardiner all chose to save Thomas after their 'Save Me Skate' performances, while ex-Pussycat Doll Ashley Roberts chose King to stay in the competition.
After discovering she was to leave, King said: "I loved learning how to skate. i just adored it. I think more people in Britain should do it."
She added: "I loved skating with Mark. He's amazing. I feel really devastated for him because I'd like people to see his skating more."
Meanwhile, Henretty said that King had been "a pleasure" to skate with. He also revealed that his partner Cathy is expecting their baby any day and was watching from home.
He said of his accident: "Sorry about the stress. That might have sent her into labour!"
Dancing on Ice continues next Sunday (January 27) on ITV.
Photo gallery - Dancing on Ice week three:
Copyright: Matt Frost/ITV/Rex Features