He is right and this is why: because ambitious, pushy and affluent middle class parents are 'buying' their kids' school places by extra tuition and hot-housing.
I am neither pushy nor affluent.
I have sacrificed, scrimped and saved to send my son to prep school for the past seven years, and I was hopeful he would get into a grammar.
This year, he sat entrance exams for two such schools and did not get offers at either, despite being academically able - in all the top streams at school, and consistently getting straight A report cards. But where competitive entry is concerned, this is just not enough – what he actually needed was to have given up all his free time, and essentially his childhood, for the preceding year and to be trained in the art of completing exam papers and second guessing the questions.
For the past 12 months – in some cases longer - dozens of children of our acquaintance have been having extra tuition for competitive grammar school places. Talk at the school gate and in the coffee shops has long since stopped being about Downton or Strictly. Instead, intense chatter prevails about the best websites to get past exam papers, the best books of verbal and non verbal reasoning tests, how to snare the best tutor – and keep him/her. I even heard of 'gazumping' where parents would offer extra cash on top of the hourly fees in order to get the most coveted tutor for their child.
I just couldn't buy in to it – I couldn't afford to, but also, I would look at my son bursting out of school at 4pm, full of pent up energy after a seven-and-a-half hour day of studying, and want nothing more for him than to tear around the park with the dog, or chill on the sofa with a DVD.
I did not want to be the parent who was giving him his after school snack in the car as we rushed across town for yet MORE schooling, or the mum whose handbag was full of pages from Ten Minute Tests to squeeze in even more revision in traffic jams or dentists' waiting rooms.
We knew children – too many children – whose weekends consisted of timetabled study programmes. Their lives – at the age of nine and 10 – became full of missed parties, cut short sleepovers and declined tea invitations in favour of one-to-one sessions with visiting teachers, or even 'study sessions' with other friends.
Don't get me wrong, education is very important to me, which is why I made the decision to send my child to prep in the first place, but it also needs to be engaging and fun and I did not want my little boy to be 'trained' to pass an exam, or to make study his whole life.
And these are not just the concerns of an overly cautious mum. Earlier this year, Christopher Ray, chair of the Headmasters and Headmistresses' Conference, not only warned of the pressure parents put their childrenunder to pass exams in the first place, but also the ongoing struggle hot-housed children then endure to keep up after being tutored through the entrance process.
Mr Ray questioned whether these children would make it into the sixth form at 16, and suggested that one of the reasons they might not would be because they had been 'over-tutored' for their initial exams, and then could not cope as they progressed through school.
I share his views, and to my mind, they run parallel with those of Sir Michael Wilshaw. The middle classes have commandeered the grammar school system because they have the money to do so, and if grammars are to continue to exist to give brighter children a chance to excel academically, then the entrance requirements need to be changed; past papers should not be made available, tutoring should be discouraged and EVERY child should be sitting the exams on an equal footing. Selection should be made on interview, based on past school reports and achievements, and not on the results of a two hour test that a child has conditioned to pass.
"The problem is that doing the tests is accompanied by a very expensive private tuition industry. Everybody knows that," she said. "The affluent parents can work that system very, very well.
"There's really no way to create a tutor-proof test so while you've got entry by selective test, it is going to benefit the better-off families - and that is why Michael Wilshaw is right to say that it is not a system for the future of this country if what we want is all children to do well and the gaps to narrow."
Of course children who are academically able will flourish in any good school; comprehensive, academy, grammar or independent, but how unfair that for those parents who wish for a grammar school education for their children, that the reality is, their kids' natural ability is not enough. They have to be able to afford it, and sacrifice a whole lot of their children's lives in order to achieve it. Today grammar schools only benefit those who have a life full of opportunity, anyway.
What do you think? Are grammar schools essentially turning into private schools by another name? Should children from all walks of lives and abilities simply attend their local school, and expect to do well, as Sir Michael wants?