Two leading think tanks have urged the government to start planning for the legacy of a successful 2012 Olympic bid.

A report published by the Institute for Public Policy Research and Demos said that without careful planning the UK risks following previous host cities in struggling to ensure there is a lasting legacy to the games.

The study, "After the gold rush", says that previous games have not always delivered on promises of long-term employment, social housing and increased sports participation.

But Barcelona in 1992 demonstrated that by integrating the games within a broader regeneration strategy it is possible to deliver some lasting benefits, said the think tanks.

The call for careful planning was backed by culture secretary Tessa Jowell in her foreword to the report.

"It is particularly important to understand the message that only by embedding legacy planning into every aspect of our preparation for the games will we make the most of the opportunities available to us," she said.

Among the proposals put forward was an "Olympic employment taskforce" to match the needs of employers with unemployed people.

And an "Olympic volunteer army" could contribute time and enthusiasm in the months and years leading up to the games, working in their local community as well as in London, said the report.

Anthony Vigor of the IPPR said that the games would be "a lifetime opportunity to build new infrastructure and benefit local residents".

"It is clear that a significant element of any Olympic legacy has to be delivered before the games begin," he said.

"But claims about the long term benefits of Olympic games made by previous host cities, often do not stand up to scrutiny.

"By working together from the outset, all those involved have a real opportunity to create a sustainable Olympic legacy for the UK."

And Demos researcher Melissa Mean highlighted the dangers of "white elephants"

"It looks like London 2012 have taken the necessary precautions against this, but a sustainable legacy must mean more than just avoiding building facilities that have no post-games use," she added.

"The UK has the chance to think creatively about the positive social, cultural, environmental and employment value of the games - something that should make its bid a winner in the eyes of the IOC and the local community in the years to come."