The shadow justice secretary is a serious politician with progressive beliefs no doubt shaped from his time as a human rights lawyer and board member of Liberty.
He is a man Liberal Democrats in the capital could do business with, much more so than the old New Labour pretenders to the mayoral crown Sir Robin Wales and Tessa Jowell.
The son of a bus conductor from Tooting would have broad appeal and this presents a dilemma for Lib Dems.
We do not appear to have a front-runner at the moment and our flag-bearer last time around, Brian (now Lord) Paddick, scraped an embarrassing 4.2% in 2012 despite holding his own in hustings debates.
London is set to remain a two-horse race for some time despite – as I have previously argued – much of the capital being Liberal in nature.
Ken Livingstone was 3.7% behind Boris Johnson at the last election and while Ken’s reputation and failure to offer a fresh new programme would have cost him some votes, BoJo has shown a continued ability to buck the trend of Tory unpopularity.
The coin is still spinning as to whether Boris runs again or heads for parliament to try and lead the Tories but if he did contest a third term who would bet against Boris’s larger-than-life personality winning again regardless of the trail of destruction behind him, from his abject failure to deliver election promises to closing fire stations.
London simply cannot afford a Boris third term and more than ever needs a serious and progressive mayor.
If Sadiq becomes Labour’s candidate I really think a grand coalition with the Lib Dems would benefit both sides and demonstrate consensus politics on the Left around issues we can agree on.
The Lib Dems have little to gain by standing a mayoral candidate in 2016 other than another hiding.
It makes much more sense to back Sadiq and have a deputy mayor with real power, perhaps someone like Caroline Pidgeon, and a coalition cabinet with a brief to both defuse the all-powerful office of the mayor and improve decision-making.
In return Labour could replicate the favour in Assembly List elections. Post-election there could even be a joint party conference in London to elect the cabinet members with reserved places for Lib Dems.
Such a coalition would benefit from Sutton’s experience in local crime and safety partnerships in contrast to the Boris / Stephen Greenhalgh dictate-from-above approach and meaningless 20% targets arbitrarily imposed on every area of policing.
Lib Dems have also been leading the debate about devolving power and democracy to a local level and reinventing local government by taking on new services, for example energy generation. All these areas would benefit from a strategic lead from City Hall.
A coalition would be more effective in pushing the mayor to deliver social housing and be more creative about improving transport while reducing fares. At the same time the Lib Dems could learn from Labour about the need for action to achieve equality rather than merely hoping for it.
It would show in practice that Lib Dems have serious policies and expertise to benefit Londoners and that progressive forces can unite effectively against Conservativism when the occasion demands it.
By Lester Holloway @brolezholloway