While the grammars elevated many children from working-class backgrounds to positions at the top of large public corporations and even the office of Prime Minister, the comprehensives championed by the liberal left and accepted by the Tories proved less successful.
On average 2.6% of grammar school children received free school meals compared with 13.4% of children across all state secondary schools.
"School budgets are at breaking point".
School leaders have slammed the decision to spend "scarce funding" on expanding the selective state schools.
Parents who can afford to send their children to independent private schools - including left-wing, anti-grammar politician such as Labour's Diane Abbott - have increasingly chosen to do so.
Children from more deprived backgrounds on average do better at grammar schools than in the comprehensive system, but these schools select a disproportionate number of children from wealthy families.
However, schools review their admissions policies each year and since this investigation was conducted, several have updated them.
Another way is to have lower pass marks for lower-income children.
"High-ability students do just as well in good non-selective schools as they do in good grammar schools, and funding is therefore better spent on creating places in the former rather than the latter".
Are grammars just playing catch up?
Pupils tend to travel further to attend grammar schools than they do to attend comprehensives.
The Archbishop of Liverpool has condemned the British government after it broke a manifesto promise to allow new Catholic schools to open.
The plans to set up a formal agreement between grammar schools and the government to widen access for disadvantaged pupils were delayed in January by the cabinet reshuffle and appointment of Damian Hinds and the new education secretary.
It is a odd twist of fate that today's grammar school announcement better reflects the priorities of the education secretary who was sacked rather than those of the prime minister who sacked her.
However, Maureen Johnson, headteacher at Weald of Kent Grammar School, was "pleased to hear the Government is still committed to increase parental choice through offering grammar schools the chance to expand".
The 50% cap on the proportion of pupils that faith schools can admit based on religion will remain, but funding will be given to create new voluntary aided schools - which are run with local council involvement - if there is local demand.