Mission impossible is how one friend last autumn described my new role as commissioner for London schools. Her comment crossed my mind last month as the Prime Minister and Education Secretary unveiled their new strategy for the capital’s schools, London Challenge. Despite the upbeat presentation, press reports were depressingly negative.

The committed teachers who work in the city’s most challenged areas could be forgiven for thinking the “name, blame and shame” approach, which has caused so much damage to morale in recent times, was still alive and well.

Sceptical critics in the broadsheets argued the initiative simply rehashed existing policies in a London context and that funding problems would make any shift of mood well-nigh impossible.

They are only half-right. The enormous potential of London Challenge is simply stated. Its aim is to have the same effect system-wide that individual teachers and schools often have on breaking the cycle of disadvantage and failure. The correlation between socio-economic and educational failure is well-documented and is nowhere stronger than in big cities.

The legitimate question is why there should now be transformation across London when it has not been done before. There are three main reasons why I believe it can be done.

First and foremost, are the teachers. Despite concern about staff shortages, London is fortunate to have an unusually large group of young and mid-career teachers at the height of their teaching powers. They have been holding schools together in times of great turbulence. The quality of these teachers is at the heart of any hope of transforming opportunities for children. That is why I welcome the improvement in teachers’ pay in inner London and the fact that the School Teachers’ Review Body has promised to address pay for the whole of London next year.

But it is in the vital area of professional development that London Challenge has proposed something significant: a new chartered London teacher certificate will enable teachers to prove they are continually gaining new skills and expertise. Successfully completed, the new certificate will mark teachers at the peak of their profession and encourage them not just to start out in London but to spend a fair chunk of their lives there. The extra financial reward that being a chartered teacher will bring can only reinforce the message that teaching in London is a worthwhile - and long-term - experience.

The second reason why I believe the London Challenge will make a real impact is the greater knowledge we have today about how to improve schools and develop an achievement culture. It will be our task to spread good practice, helped by data that, for the first time, can help schools compare how they are doing with others in comparable circumstances. We will encourage schools to join together in collegiates and federations to help them develop methods that work.

My third reason for believing in the London Challenge is our increased knowledge about learning and teaching methods. Developments in formative assessment in marking and teaching; the understanding and use of “cognitive acceleration”; and advances in applying the theory of multiple intelligences are good examples. To these can be added new technology, yet to have a real impact, but so full of promise.

These three factors, then, are reasons to be cautiously optimistic. But - and in this respect the sceptics are correct - there is no certainty that the strategy will succeed unless it gets more money. The stark figures speak for themselves: London spends 75 per cent more per head on police and 55 per cent more on social services than the rest of the country. The comparable premium for education - the one service that has the best chance of breaking the cycle of disadvantage - is less than 15 per cent.

That must change. One of the key priorities for extra funding should be to help youngsters who are struggling to achieve. The way to do this would be to introduce a London-wide grant payable to secondary schools for each pupil that achieved level 3 or less in English and maths at the end of primary school.

This would be especially beneficial to those schools with the highest proportion of such children. The cost could be easily met by an increase in secondary budgets of 10 to 15 per cent. That would still leave relative spending on education well below that on police or social services. Such extra funding will help to ensure we succeed. Then even the most sceptical opinion-formers may start to talk about the good things happening in London schools.

Tim Brighouse is the commissioner for London schools. His article is based on a TES-sponsored lecture at the National Extension College last week