King was Livingstone’s sole challenger in Labour’s contest to select a Mayoral candidate, securing just over 31% of vote.
In her new role as as Young People’s Champion she would be responsible for delivering Livingstone’s manifesto for young Londoners including his pledge to restore the Education Maintenance Allowance for London students.
News of King’s appointment comes a week before Londoners go to the polls.
In recent days a number of high profile Labour figures, including former Transport Secretary Lord Adonis, have backed Livingstone’s campaign.
Earlier this week Livingstone denied such endorsements are a move to shore up his support within the party and encourage wavering Labour voters to back him next week.
Polling expert Stephen Shakespeare recently suggested that Labour supporters unhappy with Livingstone could be the key to a second term for Conservative rival Boris Johnson.
Announcing his intention to appoint King, Mr Livingstone said: “I was consistently impressed by Oona’s ideas to help young Londoners during the Labour selection contest. I told her then I’d steal her best policies – now I’ve gone further, asking her to lead on our work with London’s young people and I’m delighted that she’s agreed.
Livingstone promised King would “form an integral part of a fresh Labour administration at City Hall, as we work together to stand up for Londoners being hit hard by a Tory onslaught.”
Ms King added: “We can’t let the Tories get away with how they’ve made things worse for young Londoners. I want to do everything I can to help young Londoners by working with Ken as part of a Labour team that makes Londoners better off.
“Ken’s Labour initiatives from reintroducing EMA, supporting for Safe Havens, helping girls in gangs, implementing anti-poverty strategies, pre-apprentice pilots, and cutting fares show exactly how much better off Young Londoners will be with Ken as their mayor.”
Candidates for Mayor include Jenny Jones (Green party), Ken Livingstone (Labour), Lawrence Webb (UKIP) Boris Johnson (Conservative) and Brian Paddick (Liberal Democrat). A full list of candidates can be found here.
Candidates standing as London Assembly constituency members can be found here. Candidates for the 11 Assembly London-wide seats can be found here.
