Labour declared today that Boris Johnson's "2020 Vision " was "the beginning of his long goodbye" to London (the Mayor again confirmed that he won't be running for a third term) but who is the party likely to put forward for City Hall in 2016? Here's who's currently in the running.
After choosing not to stand in 2012 (he wrote that he "t hought hard  about whether to enter the contest"), the Tottenham MP has quickly established himself as one of the frontrunners for the Labour nomination, recently publishing a lengthy critique  of Boris's record. As Ken's campaign chair in 2012 he can count on the support of many of the former mayor's supporters and his well-received book on the riots Out of the Ashes further enhanced his reputation.
Asked last month by Mumsnet  whether she would consider standing, the Hackney North MP mischievously replied: "I am not ruling it in or out " Since becoming shadow public health minister she has shed her maverick image and is increasingly rated in Labour circles.
The shadow justice secretary has long been rumoured to be considering a bid and was recently appointed shadow minister for London, putting him in a strong position to win the nomination. As MP for Tooting since 2005 and a Wandsworth councillor for 12 years (1994-2006) he has long-standing links with the capital.
Since her election in 2010, the Walthamstow MP has impressed many in the party with her campaigns on knife crime  and payday loan companies . Likely to be promoted to the shadow cabinet in the forthcoming reshuffle, she is a good outside bet for the nomination.
Despite her defeat at the hands of Ken in the 2010 selection contest, King has refused to rule out another bid, tweeting  after Livingstone's defeat: "My husband asked me for first time: are you going to run in 2016? Too early to say, I said, and went back to the washing up... #londonmayor ". More recently, she told  the Guardian: "If a week is a long time in politics, come on, 2016 is too far away, and the genuine thing is it depends on my kids. I still think the London mayor is the best job in the world, but that's a different question to whether I try to run for it again".
The Dagenham MP, currently leading Labour's policy review, was urged by many  Labour supporters to stand for the nomination in 2010 but eventually lent his support to Ken. Having previously commented that he's "not interested in Westminster, or parliament really", a bid for City Hall may appeal once the review concludes.
The Labour peer and former transport secretary, who is currently advising the party on industrial policy, declared in 2011  that he "would love to be Mayor". His passion for infrastructure and grands projets makes him a strong candidate to oversee the completion of Crossrail. In a piece  for today's Evening Standard, he condemns Boris's failure to build a Thames crossing, writing that "what’s needed is action not waffle".
Westminster's favourite former New Labour minister revealed last year that he considered running  for the post and said of a 2016 bid, "I would not rule it out". More recently, however, he said  he would be "too old" (Johnson will be 65 in 2016) and that he wanted to commit to serving another full term as MP for Hull West. But given his ever-improving reputation could he be persuaded to reconsider?
And one who won't be ...
The long-standing Labour supporter has openly declared his interest in the post but recently told  the Sun that he intends to remain in comedy for six more years, putting him out of contention for the 2016 nomination. Given his penchant for attaching himself to doomed causes (the euro, the Alternative Vote) that may be just as well.