The conclusion of the Beijing Olympics has transformed the way we think about the Games and the London 2012 Olympics.

Now there is a real popular enthusiasm for the British team and a passionate public feeling that their success should be repeated in 2012.

But London 2012 will be as much about the legacy of the Games as about 17 days of glorious sport. The team that won the bid, led by Sebastian Coe, said as much.

For that legacy to be of lasting value, it cannot simply be about transforming the physical infrastructure of the stadium and park, however important that is. The Olympics must have a transformative effect on sport in London - a human legacy. If the Games turn out to be simply a glorious spectator spectacle, they will have failed. They must result in greater participation in sport, not just on the part of the sporting elite, but by young and old, in every part of the capital. How best to transform enthusiasm for the Games into a new sporting culture is the challenge - and it needs concerted thought and planning.

That is why this paper has produced its own charter for the Olympics legacy. Supported by marathon world record holder Paula Radcliffe, 2012 Organising Committee chairman Lord Coe and recordbreaking US gold-medallist Michael Phelps, the charter calls for a transformation of London's sporting culture. We hope it will be taken to heart by ministers, the Mayor and the 2012 organisers. It would require both imagination and commitment to implement - but it would bring the change we need.

First of all there can be no real prospect of boosting popular participation in sport without proper facilities. And as our poll today shows, more than a quarter of those questioned described their local council-run facilities as either poor or very poor, with a further 14 per cent saying they either had no such facilities or never used them. Some 40 per cent of respondents said they had no local pool. This is no basis for bolstering large-scale participation in sport. Lack of public swimming pools was the greatest concern: 40 per cent of those questioned demanded a pool near them.

The respondents had their own idea of how the London Olympics could deliver a sports legacy - two-thirds of them called for a moratorium on the sell-off of school and council facilities, while 46 per cent said they would like improved access to good facilities that already exist. Worryingly, the poll reveals that nearly half of children are doing less than two hours' school sport a week.

This paper's charter gives priority to preventing further damage to the sporting infrastructure by calling for a halt to the sale of public pools and playing fields. Councils and schools will always suffer from financial exigencies which will tempt them to sell sports fields and halls - but once the facilities are gone, they are gone for good. That short-termism cannot continue.

Then there is the question of the future of the sporting facilities used in the Olympics. We want them to be available to all London's schoolchildren. Of course, they are also important for nurturing the talent of a future sporting elite. But access cannot be restricted to a small stratum of top athletes - the new sporting culture should be open and democratic. It was apparent at the Beijing Olympics that some sports, such as sailing and rowing, were dominated by athletes from private schools. People should understand that they are open to children from all backgrounds.

Another of our proposals is for an Olympic Champions system, which will recruit top-class athletes to visit schools and inspire children, teachers and parents alike. Finally, we want to see sports funding ringfenced by the London Development Agency, councils and authorities, to ensure it is kept for its proper purpose. Private sponsors and businesses would be encouraged to contribute.

The benefits of greater participation in sport are very great - in terms of health, community spirit and human happiness. But they can only be achieved with political commitment and rigorous planning - and that is what we aim to encourage.