But, POGs, parents can't make a choice.
Apart from a handful of areas, such as Essex (Colchester and Chelmsford), Devon (Colyton) and Liverpool (Bluecoat), where there are a handful of grammar schools, which do not significantly affect the comprehensives, parents do NOT have a choice.
Areas such as Kent, Wirral and Lincolnshire, have a fully selective system. Those who don't pass the 11+ (the majority) have no choice at all. They go to a secondary modern (sometimes masquerading as comprehensives) and that's it. Those who pass the 11+ could in theory refuse to take up the place, but they'd be bonkers to do so, because able children would not be in a school which could offer them an appropriate education.
Most proper comprehensives can educate every child appropriately. There are all sorts of reason why so many comprehensives don't have a full range of ability, including the existence of schools using backdoor selection policies, so why make the situation worse?
Corbyn is NOT saying that able children shouldn't be given an appropriate curriculum, because they can receive that in comprehensives. Why introduce all the disadvantages of a selective system, when there are almost no advantages, which are in any case limited to a small minority?
This is pandering to Ukip deserters, pure and simple.