London assembly and mayoral elections are won or lost in the suburbs. As the votes for Ken and Boris were being counted, in my part of suburbia the election seemed to be going Labour’s way (Labour winning back the Tory-held GLA seat Brent and Harrow), yet when the dust had settled it was clear that Harrow was the exception – the suburbs had come out for Boris. Why Boris did so well in the suburbs and how those suburban voters can be won back are questions that need to be at the heart of a debate in the London Labour party on how we put together a new coalition of support to win again in 2012.

Ken’s defeat is seen in some parts of the London Labour party as being almost entirely the national party’s fault (with the media a close second). But for the national mood, so their argument goes, Labour in London would have won triumphantly again. It is true that our vote held up well: every sitting GLA member returned, and a seat won from the Tories. A triumph of good organisation wasn’t, however, enough as the Tories mobilised their own supporters equally well and successfully wooed many new suburban voters for Boris. To dismiss the defeat in London as being solely because of the wider national picture is to turn a blind eye to a series of tactical mistakes the campaign made that alienated suburban voters.

To win London back, Labour must once again convince suburban voters that Labour in London is as relevant to them and their aspirations as it is to inner-London voters. The congestion charge and the Olympics – totemic successes of Ken’s time – were not enough for suburban voters. Arguably the biggest tactical error the London campaign made was to ignore until far too late a key concern for suburban voters: crime and antisocial behaviour.

Despite the fall in crime nationally, concern about violent crime – in particular, knife crime – and continuing frustration about antisocial behaviour were the top issues in the election. Yet, except at a local level, this was an issue Labour talked about far too little. The considerable success of our Safer Neighbourhood Teams (the ward-based teams of police officers patrolling and working, Dixon of Dock Green-style, only in their area) was rarely if ever mentioned. As crime has come down nationally, fear of crime has not come down anything like enough. Yet our campaign did not appear to be addressing it. It is an issue nationally that Labour has continued to confront – the new package of measures to help tackle knife crime being just one example. It was an issue that Boris prioritised and which helped motivate returning Tory voters.

Transport is also a key concern for many suburban voters. While bus services have improved dramatically and Crossrail will deliver huge additional capacity into the transport network, our campaign did not talk up the significant investment going into the tube or address the frustrations of many south London voters with their routes in to central London.

Lastly, one of New Labour’s big successes was to reach out to voters beyond long-standing supporters. That coalition which underpinned our successes in the two previous mayoral and assembly campaigns included a significant part of the business community. This time our apparent opposition to the expansion of Heathrow Airport, with the considerable benefit Heathrow brings to London’s international competitiveness, cost us the support of some of the businesses community.

Environmental solutions must be a feature of any new campaigns for the mayoralty, but they need to be more carefully thought through. All the leading candidates opposed Heathrow’s expansion but our campaign’s high-profile opposition did us damage without bringing significant electoral benefits (the Green party polled particularly badly). In addition, our opposition to the expansion of Heathrow was particularly risky given the need for extra airport capacity to benefit those wanting to enjoy foreign holidays, a key aspiration of many voters.

As Boris already begins to run into problems, Labour in London needs a genuine debate among a new generation of candidates and activists on how to rebuild a coalition to win back City Hall. We need to consider in particular how to attract those seduced by Boris’s appeal in May, consider more carefully what our electoral offer on crime and antisocial behaviour should be in 2012, how we can build new links with London’s business community, and how we can tackle London’s environmental challenges while avoiding knee-jerk responses to ‘environmental dilemmas’.