The Olympic legacy has to be kept safe from party politics, London 2012 supremo Lord Coe said during a celebration of the Games at Labour's party conference.
The Tory peer was given a warm reception by the Labour crowd as athletes, torch bearers and volunteer Games Makers took centre stage.
Lord Coe said the legacy had to be "looked at in a consensual way" as he praised the way the Olympics had not become a "party political property".
But the cross-party consensus was broken as Labour's former culture secretary Dame Tessa Jowell and the PE teacher who mentored double gold medallist Mo Farah attacked the Government's "dismantling" of school sports.
Lord Coe said the "unity of purpose" for the Olympics and Paralympics was "almost unique in any big project".
He added: "It would have been absolutely unsustainable for this to have become a party political property. It never did."
Paying tribute to Dame Tessa he said: "We couldn't have got this across the line without you. You have been one of the longest and truest friends we have have had but you have also, when in 2010, you stayed on board, you wanted to make sure you played your part right up to the closing ceremony.
"That's what's distinguished this project and it's going to be very important as we go forward with the legacy because that has to be looked at in a consensual way as well."
Dame Tessa used her speech to warn that the Olympic legacy would be threatened by the coalition's school sports policies.
She said: "When we won the right to host the Games we made a promise - that the 2012 Games would inspire a generation. Until the election this was happening in schools across our country.
"The dismantling of this world class organisation for sport in our schools is beyond belief.
"So in order that we keep our promise to the young people of this country, I have invited the Government to work beyond party to develop the facilities, coaching and curriculum space so that we keep our Olympic promise to young people across our country.
"Building the next generation of Olympic champions starts with that - a plan for sport at every level; showing the young people of our country that when we said we would inspire a generation, we meant it."
But she said the Games had been a triumph of "modern Britishness", telling delegates: "It was a terrible summer for prejudice, for intolerance and cynicism."
Farah's former PE teacher Alan Watkinson said: "We have to invest in school sport, we have to invest in people that can change school sport.
"The withdrawal of £168 million a year for school sport and the dismantling of a world class PE and sport system was an absolute disaster."