A major international report is expected to show that UK students are lagging far behind their peers in Asian countries in reading, science and maths.
Global school league tables assessing countries performances in the three areas will be published this morning by the Organisation for Economic Co-operation and Development (OECD).
School systems in South Korea, Japan and Singapore did well in a similar study three years ago, while the UK was an average performer.
Around half a million pupils around the world took the tests, including students from England, Scotland, Northern Ireland and Wales.
More top news
David Cameron has been urged to visit Calais to witness the impact of the migrant crisis "first-hand".
The cost of filling up an average diesel car has dropped by £3 in just a month, new figures have shown.
Singer Gwen Stefani and her British husband Gavin Rossdale are to divorce after almost 13 years of marriage.