There is a tendency for everyone in politics, both politicians and commentators, to make single sweeping judgements based upon what ultimately are a myriad complicated reasons that swing votes one way or another.

So for Labour politicians doing the media rounds last night, getting hit hard by the expenses scandal became the most common attempt to explain the disastrous results. Meanwhile most of the commentators seemed keen to bring everything back to the question of Gordon Brown’s leadership, and how MPs would react to results that were even worse than expected.

Amid a night of bad moments, watching the racist BNP win representation in the European Parliament delivered the worst. But I was struck by something BBC political editor Nick Robinson spotted early on in the evening, namely that despite the BNP winning two seats, the numbers voting for them actually fell. In other words, it was votes which would normally be expected to go to the mainstream parties, but which never materialised, which saw the fascists over the line.

Of course those who say it was a day of shame for Britain, and for Labour, that the BNP won these seats, are right. But in addition to going out and trying to win back those who switched from Labour to BNP, Labour also has to find out in detail why those who stayed away did so, and whether they can be engaged sufficiently, and persuaded once more of Labour’s values and purpose, to come out to vote for the Westminster Parliament.

We will all have our theories about the record low turnout, and the politician on the results programme, or the commentator given thirty seconds to sum up, have to boil everything down to simple definitive propositions.

But it was interesting that when, scratching around for a ray of hope in the local elections I blogged on Labour’s by-election win in Lambeth a couple of days ago, quite a few messages came in from other local parties who had similarly bucked the trend, and similarly said they believed they did so as a result of sustained local engagement.

The Lib Dems have always had the reputation as being the best at pavement politics, but Labour are going to have to match and better them.

The party nationally is not going to have the kind of funds that have been available in previous general elections. Local campaigning, and in particular engaging with those stayaway voters, is going to be crucial to Labour having any chance of avoiding another dreadful result whenever the general election comes.

As MPs head to the meeting of the PLP tonight, all of the focus media-wise will be on the Prime Minister. But in every area where ground has been badly lost, MPs all have to look to themselves and their roles as figures of leadership in local campaigns. It is not just about the leader. It is not just about expenses. It is about getting hold of the raw data on who switched, who stayed away, and systematically working your way through a lot of shoe leather and a lot of knocked doors.

I also wonder whether the main parties do not now have to reconsider the policy of never engaging in direct debate with the BNP. The lesson of their brief flirtations with local power is that when they are subjected to real political debate, decision making, and providing solutions rather than slogans, they fade quickly.

Out in Kentish Town this morning, I ran into someone who said she was ‘angry and ashamed’ that we now lived in a country which defeated Hitler but had two fascists taking public money to present a ghastly face of Britain to Europe and the world.

She also admitted that she hadn’t voted because she was so angry about MPs’ expenses. There is a lot of anger out there at the moment. Labour has to turn some of it into activism.