London school success is largely down to the London Challenge under the last Labour government, but to bring that up now is a risk because:
It was clearly a very London-centric policy although it was partially rolled out in other areas later
London has some real advantages in terms of teacher recruitment and retention that the places with the worst quality schools don't have (e.g. post-industrial or former fishing towns)
London has different demographics (fewer pupils from the lowest-achieving groups)
It costs money and spending on education is frivolous and wasteful when we need more nuclear weapons and warships
London school success is largely down to the London Challenge under the last Labour government, but to bring that up now is a risk because: