Grammar schools lead in GCSE results
All but one of the state schools rated top in terms of GCSE attainment this year are selective schools, an analysis of official figures show.
It also reveals that grammars are disproportionately over-represented when it comes to the top secondaries on progress.
The findings come amid a continuing debate about selective schools, sparked by a push from Prime Minister Theresa May to overturn a ban on the creation of new grammars.
The pledge was included in the Conservatives' general election manifesto last year, but in the wake of the result, which saw the Tory party lose their majority, there has been little movement on the policy.
According to a Press Association analysis of official secondary school performance data, 99 of the top 100 schools in terms of GCSE results are selective.
This is based on the Government's "Attainment 8" measure, which looks at the achievement of a pupil across eight qualifications, including mathematics and English, which are double-weighted, three further qualifications that count in the English Baccalaureate (EBacc) measure and three other qualifications that can be GCSEs or any other approved equivalent course.
The one comprehensive to make the top 100 was Dame Alice Owen's School in Potters Bar, Hertfordshire.
It is listed as a comprehensive school in the Government's data, although according to its website, the school does select 65 children out of 200 each year based on aptitude and abilities determined by the Governor's Entrance Examination.
It also selects a further 10 pupils through music aptitude tests.
The analysis also looked at the top 100 schools in terms of pupil progress, using the Department for Education's key "Progress 8" measure - which is used to assess whether schools are under-performing.
It found that 29 selective schools were in the top 100 based on this measure, along with 68 comprehensives. The final three were other types of state school.
As there are only 163 grammar schools in England, it means that they are disproportionately over-represented, with almost a fifth (18%) in the list.
Jim Skinner, chief executive of the Grammar School Heads' Association, said: "It's reassuring to see, as we would expect, that selective schools are dominating the Attainment 8 measure, but it is perhaps more significant that they are disproportionately well represented in Progress 8.
"It shows that not only are students in selective schools achieving highly, they are making very good progress from the high levels they enter the school with."
The Government judges school performance based on Progress 8, rather than Attainment 8.
Progress 8 is based on the progress a pupil has made between the end of primary and the end of secondary school, and their results across eight GCSEs compared with their achievement of other youngsters with similar abilities.