So I’ve done the marathon. Three hours 28 minutes and 52 seconds. Just inside my 3:30 target and just outside the top 10 per cent of runners overall. I started writing this on Monday morning and was still as stiff as a board, sunburned and sore all over.

The first fifteen miles were fine with my second 10 km my fastest. Between 15 and 20 it started getting rough and then…

Everyone tells you how tough it gets at the end but nothing can really prepare you.

When I got to 22 miles I was still three minutes ahead of my target pace but every few seconds I was being overwhelmed by the need to stop running. Between 22 and 23 I did walk for a minute and then between 23 and 24 for another 30 seconds until someone in the crowd caught my eye and urged me on.

I think the final mile must have taken getting on for 10 minutes and even at 400 metres I would have happily paid £10,000 to have been transported to the finish.

As the pain subsides I can remember the high points. Tower Bridge at the halfway point and running between the skyscrapers of Canary Wharf as you get past 20 miles are particularly memorable.

I found catching up with novelty runners a good motivation. I was determined not to end behind Scooby Doo (nine miles), Spider Man (15 miles), Elvis (20 miles) or Superman (21 miles and again at 24).

One the things that kept me going was all the kind people who have sponsored Oxfam through me so thanks to them for helping me over those last awful miles. With the additional cash and cheques I was given over the last couple of days I made the £2200 target.

It was the fundraising that won me a compliment from Conservative Leader David Cameron when he spoke at the RSA on Monday morning. As a lifetime Labour Party member this was a bit strange, but being chief executive of a fiercely independent organisation like the RSA it can only be good that a leading politician chooses to join our debate about ‘pro-social behaviour‘. The Cameron speech was a useful contribution to the debate.

Sometimes the discussion about how we encourage people to give more back can seem rather woolly and it certainly tends to get treated that way by the political media.

I think it can provide the basis for a more relevant type of politics, with right, left and centre variants of the analysis depending on your views of social justice and the state.

But anyone who has a tendency to under-estimate the contribution to social change that can be made through voluntary collective action should have been in Greenwich Park or anywhere between there and the Mall on Sunday.

The charitable efforts of the runners of all different ages and backgrounds – many of whom ended up running and walking in all kinds of costumes for five or six hours in a baking hot day – and the incredible support of the hundreds of thousands thronging the route reminds us what sacrifices and celebrations we are capable of when we turn our minds to it.

Those of you who have read my speech or essay on pro-social behaviour (thanks Mum) may recall that one of my arguments concerned the inadequacy of ‘majoritarian’ democracy to today’s social and political challenges. By ‘majoritarian’ I mean the view that the rule of law, regular elections and competition between parties are a sufficient basis for a successful democracy.

This can be contrasted with arguments for a more participative system in which citizens have a direct role in decision making and/or a pluralist system in which power is more widely diffused, for example through extensive decentralisation to cities, towns and neighbourhoods.

I have two recent reminders of this debate. The first comes in a refreshingly frank letter from one of our MP Fellows (a Conservative in case you’re interested). He describes how the task of being a democratic representative is being made ever more difficult by the decline of community organisations. Even where such organisations exist, he adds, they tend to be strongest among those who are already adept at having their opinions heard, particularly the well-off retired.

Very different factors lie behind the problem of understanding what communities want and engaging people in informed debate. The diversity of society (in relation to income, identity, attitude and lifestyles) makes representation more complex while the intensity of work and the opportunities of consumerism mean fewer people are inclined to get involved in community organisations.

The other prompt is my membership of the Commission on Councillors set up by Communities Secretary of State Ruth Kelly. The Commission is charged with exploring why more people (and particularly young people) don’t want to stand to be councillors, and proposing ways to address this deficit. There are some obvious reasons including the level of allowances, problems with time off from work and the low prestige of councillors in the wider community. Indeed only 4 per cent of the population have ever even considered standing.

The Commission was launched last week and our focus now is on listening and learning, but if I do bring a predisposition to our deliberations it is to think that we should address the issue of councillor recruitment in the context of the wider state of representative democracy. As long as the attitudes of citizens to politicians are framed as they are now it is difficult to see why anyone would want the hassle. Add to that the fact that putative councillors have to work their way through the hollow bureaucracy of local political parties and maybe we should be surprised the 4 per cent isn’t lower.

Fiercely protecting its independence, the RSA can sometimes give the impression it is above politics. But as part of our work on ‘pro-social’ behaviour we need to think about why politics isn’t working. Not in order to add to the lazy criticism of politicians but so we can develop practical ways to help reconnect the political process to today’s communities. I’m keen for example that we invite local councillors to Coffeehouse Challenge events – on the strict proviso that their status in the discussion is no different from any other participant.

The competitive nature of politics and an understandable fear of how the media might exploit candour can make politicians shy of describing just how hard it is to be an effective representative. Between the superficial apathy of voters and the disenchantment of politicians there is an important space for the RSA to provoke debate and innovation. And in case this doesn’t feel like a priority, look at the research from Cambridge University published yesterday. In assessing levels of contentment across the citizens of Europe the research suggested that the best explanation for the surprisingly low levels of contentment in the UK (given our affluence and stability) lay in our lack of confidence and trust in political institutions.