'Prepare pupils in England for international tests'
Pupils in England should be prepared for international education tests, the chairman of a group of hundreds of secondary schools has argued.
The latest rankings in the Programme for International Student Assessment (Pisa) will be published on Tuesday.
Sir John Rowling, of the Performance in Excellence (PiXL) Club, says Pisa tests are so politically important that pupils should prepare for them.
Results for England may cue "another blast of negativity", said Sir John.
The PiXL club is a group of some 800 schools dedicated to boosting pupils' exam performance at A-level and GCSE.
Some of its methods are controversial, for example entering the same student twice for the same GCSE subject, which the government has said can amount to "gaming the system".
In an interview with the Times Educational Supplement website, Sir John criticises the government's current attitude towards the Pisa tests which are sat in reading, maths and science, every three years, by a random sample of 500,000 15-year-olds from more than 60 countries.
The last set of rankings, published in 2010, were dominated by Asian school systems. Scandinavian countries had the best results in Europe, while scores from UK countries dropped to the middle of the table.
At the time, Education Secretary Michael Gove said the results showed an "urgent need to reform our school system".
Sir John says this sort of judgement is "damaging".
"There is huge suspicion that it is convenient politically at the moment to take tests that say we are flopping down the tables because it proves the point that is being made stridently that education is broken.
"Make no mistake, on December 3, the morale of the profession will take another whack around the ears. It is almost certain.
"Schools will be told, 'Again you're hopeless', 'Again you've messed up', 'Again you're no good', 'Sort yourselves out'. All that sort of stuff doesn't do any good and it doesn't solve the problem either."
Sir John suggests that England may be losing out because other countries take the tests more seriously and do more to ensure that pupils perform well.
The former headteacher says one solution would be to familiarise pupils with the style of the tests.
He told BBC News that because the tests are taken by a minority of pupils they are not taken seriously and "nobody bothers".
"It all seems so far away it doesn't seem to matter - but when politicians get hold of the results it matters a great deal."
He added that no-one would think of entering any other exam "from driving tests to Oxbridge exams" without preparing - but says schools are "dissuaded" from preparing pupils for Pisa.
"Maybe that's what the government wants. Maybe it's what Pisa wants too, and if everybody else is doing that, fair enough," he said.
But unless other countries did the same "you are not comparing like with like".
A spokesperson at the Department for Education told the BBC while it wanted children to do well "international comparisons - whether Pisa in 2009 or the more recent OECD adult skills survey - show our education system is not keeping up with the rest of the world".
"This puts our young people at a major disadvantage when competing with their peers from abroad for jobs.
"We are reforming our education system to reverse this situation and give our young people a fighting chance in the global race."
Malcolm Trobe, deputy general secretary of the Association of School and College Leaders, said: "Most important to young people are the qualifications they gain in this country.
"So we should focus on qualifications that prepare them for adult life, for further and higher education and employment.
"Pisa tests are experimental, comparative tests and we need to make inferences from the results extremely carefully."
The National Foundation for Educational Research (NFER), which administers Pisa in the UK, said it did not recommend teaching to the test.
Rebecca Wheater, of the NFER, said: "The Pisa survey is a research project and to treat it as a high-stakes test would misunderstand the purpose of the survey."