London mayor Boris Johnson said there were "insuperable obstacles'' based on the cost and shape of the venue in Stratford, east London, stopping a top-flight club moving in.

But he did not totally rule out the chances of a football club such as Leyton Orient or a rugby league club moving in after 2012.

Under legacy master plans unveiled on Tuesday for a six-week public consultation the stadium will house a secondary school for about 500 pupils, a National Skills Academy for sports and leisure industries as well as a centre for the English Institute of Sport.

The aim is that the £9.3billion Olympic project will help revive the deprived district with beautiful parklands, reclaimed waterways plus outstanding sporting, educational and cultural facilities.

West Ham had been linked with the stadium, which could cost as much as £550million, but London 2012 had always insisted it must have an athletics use.

The stadium will be shrunk from an 80,000-seater venue to a 25,000 capacity after the Games.

The previous London Mayor Ken Livingstone had said the stadium as part of the Olympic Park would cost £10million a year to maintain if an anchor tenant could not be found.

Johnson said "that (public) money is still on the table'' but did not give details about where it would be distributed from.

Of the hunt to find a permanent top-flight football club for the stadium, Johnson said: "In the end there were insuperable obstacles to do that.

"With the shape of the stadium it would have cost far more to have created a stadium suitable for Premiership football even if there had been a Premiership club willing to come to the table.

"It will be a wonderful stadium for athletics. It will cohere with everything we are planning in the Olympic Park.

"We could have spent twice the money and not have got anything better.''

Olympic Minister Tessa Jowell said: "We could not have proceeded with a Premiership club because it would have cost a lot more.

"A lot of these discussions will go on but what we have now is a stadium with a focus on sport and training young people.''

On the prospect of rugby possibly being based at the stadium, Johnson said: "If a club tenant comes forward with a sensible and coherent offer which makes sense for us and other people of course we will consider it.''

There were also renewed promises that even within the current recession the £9.3billion Olympic project, which has been struggling to find private backers, will not bust its budget.

"Our intention is to use the £9.3billion to ensure we can attract investors and people from around the world to this area,'' claimed Johnson, "£9.3billion is good seed money.''

Other sporting venues including the Aquatics Centre and Velodrome will be kept for community and elite sporting use under the plans. They may also be used to stage major events.

The plans also include a range of new sport facilities in and around the Park such as football, hockey, tennis and mountain-biking to be left after the 2012 Games. There are also proposals to build 10,000 new homes in addition to those in the Olympic Village.

Educational sites include three new primary schools, a secondary school and a sports academy. A new arts academy and primary school have also been earmarked in the Olympic village.

Earlier Dame Kelly Holmes said it would be wrong if athletics did not benefit as part of the legacy of the London 2012 stadium.

The 800-metre and 1500-metre champion from the 2004 Olympics said: "We have to be a nation with a national stadium. Crystal Palace has been our national stadium for many years and that is in need of complete refurbishment.

"Of course we have to have a track and field stadium. In Europe, football and athletics are all played in these national stadiums so why can't we do that kind of thing?

"Olympic stadiums get cut down in size (after the Games).

"There is no reason why it cannot be used for other needs as well. Schools will be able to use these facilities. An athletics track has a field in the middle of it so it can be used for many things.''