Comment: ministers must now guarantee a lasting legacy

But according to reports from the New Economics Foundation and the Commons Public Accounts Committee this week, the Government hasn't thought that through sufficiently either.

The PAC declares that even with a revised budget of £9.3 billion, (more than twice the original estimate), the Government "did not specify precisely what will be delivered for this money, including the legacy benefits". The economics foundation says without "cast-iron guarantees" in 2012 plans, "the Games will fail to leave the promised positive local legacy for the poorest residents of east London".

It was the legacy, especially the impact on five of the most deprived local authorities in the UK, which persuaded the International Olympic Committee to pass the torch to London. There are many forms of legacy, but the Games will have succeeded if they transform the East End and the lives of Eastenders. This is the best opportunity in living memory.

London is growing east, with an additional population the size of Leeds arriving around the Thames and Lower Lea within 20 years. The Olympics provide a catalyst to regenerate in ways which accommodate this growth, not via a lowest-common-denominator solution. The Games can raise the bar for planners and developers and engage and energise the communities who live there.

The Mayor must provide political leadership and work with business to promote a clear vision of what the East End can become and to identify the resources which will make it possible.

The Olympic Park is a stone's throw from the City and Canary Wharf, two hours from Paris via Stratford International and a DLRride from the rest of Europe via City Airport. Why wouldn't this be the first choice for a French company to base itself in the UK or an Asian investor as a European HQ?

The vision also might build on the East End's potential as a tourist destination. East London already has ExCel and the revitalised O2. It will soon have the Biota aquarium at Silvertown and the Olympic pool, stadium and velodrome. The vision must offer routes into work, better housing and a quality of life which can re-awaken the aspirations of east Londoners and attract new Londoners. Wind turbines, waterside pubs, mosques, churches, pavement cafÈs or cricket fields would help to create a new London quarter.

Government must acknowledge the need for infrastructure beyond the Olympic Park. Developers are ready to build homes, offices, shops and factories. But they need the Government to commit to providing roads, bridges, schools and health centres, or the East End will remain a place where people are reluctant to live and developers reluctant to invest.

We cannot sentence another generation of east Londoners to poor-quality housing or to a barren landscape dotted with Olympic white elephants.

Thanks to the controversy over the Olympic budget, the Government now has a miserly obsession with spending as little as possible. But a lasting legacy depends on government not extracting every penny it can from the Olympic site after the Games. Spending a little more and a little more wisely on the necessary underpinnings may be the cheapest way of securing East End transformation.