The UK is still lagging behind leading countries at education and has made little progress in international rankings since results three years ago.
The influential Pisa rankings, run by the OECD, are based on tests taken by 15-year-olds in over 70 countries. The UK is behind top performers such as Singapore and Finland, but also trails Vietnam, Poland and Estonia. The OECD's education director, Andreas Schleicher, describes the UK's results as "flat in a changing world".
In maths, the UK is ranked 27th, slipping down a place from three years ago, the lowest since it began participating in the Pisa tests in 2000
In reading, the UK is ranked 22nd, up from 23rd, having fallen out of the top 20 in 2006
The UK's most successful subject is science, up from 21st to 15th place - the highest placing since 2006, although the test score has declined
After the last round of rankings, published in 2013, there were warnings from ministers in England that results were "stagnating" - and reforms were promised to match international rivals.
