London mayor Ken Livingstone has ruled out any possibility of a football club taking over the Olympic Stadium once the 2012 Games are finished.

The stadium has been earmarked to become a permanent athletics venue but with its capacity reduced from 80,000 to 25,000, there have been persistent suggestions West Ham or even Tottenham could use the ground.

However, Livingstone insists the International Olympic Committee (IOC) would block any move to change the stadium's use post-2012 because London have already given legally-binding guarantees about it being a future athletics venue.

Speaking at a sports industry conference in London, Livingstone said: ''After the fiasco of Picketts Lock, what was decisive in shifting some votes was that there is going to be a world-class athletics venue at the centre of a transport hub in a great, modern city for the next 30 or 50 years.

''I can't make any change to that without the IOC agreeing. If I and Seb Coe were to go to see Jacques Rogge and the IOC and say 'we know we promised you an athletics stadium but we would much rather have West Ham in there as they would make more money out of it', they would simply say 'we have a contract and you can get lost'.

''The deal we made is that it's an athletics stadium and we have a legally-binding contract which is more like an international treaty.''

Livingstone, one of the four members of the ruling Olympic Board, also said London organisers had learned the lessons of the Wembley stadium saga.

He added: ''We have opened the tube station so people can get there but it's not going to be used until next year's cup final.

''If there has been anything stupid about the way it has been gone about, it's the idea that you simply draw up a contract with someone to build it and transfer all of the risk on to them. At the end of the day, if it gets sufficiently nasty they can go into liquidation and that's the end of that.

''The lesson we have got out of the Multiplex and FA problems is that adversarial contracts are not going to be what it's all about.

''You actually want something where LOCOG and the ODA (Olympic Delivery Authority) have a working partnership with the developer and not simply arguing about who pays if there's a cost over-run, so when problems occur you get to hear of it and they are not hidden away.''

Livingstone also made it clear he will fight dirty to ensure the 2012 Olympics are completed on time and to budget, and re-ignited his row with the Reuben brothers by insisting he will be ''every bit as unpleasant as they are'' to keep the preparations on track.

He has accused Simon and David Reuben of destabilising the consortium responsible for the Stratford City development, in which they hold a 50 per cent stake, and said they could cost the public up to £700m.

Livingstone said: ''We have had eight months of polite negotiation and every single deadline has been missed.

''Simon Reuben goes into every meeting screaming and shouting and I just thought it was time the Reuben brothers knew I would be every bit as unpleasant as they are.

''If they fail to deliver by 2008 we will step in.''