""There are some comprehensives where aspirations are so low that even just turning up to school is considered an achievement"
Hmm - even Knowsley, which allegedly has the worst schools in the country, had 37.4% of pupils getting 5 GCSEs at A*-C inc English and Maths in 2015. So like Bertrand I'm not entirely convinced by this assertion. There are a handful of UTCs and studio schools which are badly failing, but many of these have now been shut down.