No longer world stars?
The Programme for International Student Assessment (Pisa) study, which examines the performance of 15-year-olds in English, maths and science, is expected to show a slip in England's rankings.
It will lead to more pressure on ministers, who are already under fire after a report on 10-year-olds' reading published this week revealed England had dropped from 3rd to 19th in the Progress in International Reading Literacy Study (Pirls), which included results from 45 countries and provinces.
The study found pupils in England were less likely to enjoy reading than those in most other countries and more likely than most to play computer games. The findings led Ed Balls, the Schools Secretary, to call on parents to do more to urge children to read at home.
The Pisa results are set to be even more embarrassing for the Government than when the tests were carried out in 2003 and scores for England's 15-year-olds were ruled invalid because not enough schools could be persuaded to take part.
Last time England's rankings were published officially, in 2001, ministers celebrated as it finished near the top of the international league table.
Michael Barber, then head of the Prime Minister's delivery unit, said: "We are stars." But some saw it as a blip. Professor Alan Smithers, of Buckingham University, said that year's maths result in particular, in which England came 8th out of 32, was out of step with other surveys.
There is also less room for improvement this time as England was placed seventh in reading and fourth in science in 2001.
England was outshone in this week's Pirls report by countries including Russia, now top of the table, followed by Hong Kong.
England's drop in ranking, the largest after Romania's and Morocco's, contrasts with its national test results for 11-year-olds, which have been largely stable since 2001. The proportion reaching the target level in English has risen slightly from 82 per cent to 83 per cent.
The drop in England's average score in the Pirls test, which was taken last year by 4,036 pupils, was mainly due to lower results among pupils who normally gained higher scores. Responding to the findings, Ed Balls made little mention of schools, and instead called for parents to promote reading.
"The study shows our highest-achieving children are reading less, with children's busy days leaving less time for books at home," he said. "Parents are saying that it is difficult to strike a balance between play at home and schoolwork, between reading and watching TV."
The Conservatives called for earlier reading tests. But Steve Sinnott, National Union of Teachers general secretary, criticised tests and the curriculum for "sapping young people's enthusiasm of reading for pleasure".
Liz Twist, of the National Foundation for Educational Research and co-ordinator of the study in England, said the rankings were crude. "This is not the Premiership football league," she said.
Fall in primary reading, page 14.