Civil servants have refused to apologise for a statistical “mistake” that could have threatened the future of many small schools.

In February, the then schools minister Stephen Timms released statistics to Parliament which suggested that 11-year-olds in small primaries (fewer than 10 pupils in each year group) perform less well than pupils in larger schools.

According to the Department for Education and Skills, children in small primaries were almost twice as likely to fail to reach the expected level in key stage 2 national tests (“Surprise as small-school pupils lag behind peers”, TES, March 1).

In fact, the reverse is true. New figures given to The TES show that small schools outperform their larger counterparts (see table, right).

“The February statement was very damaging,” said Mervyn Benford of the National Association for Small Schools (NASS). “We don’t blame Stephen Timms, he simply read out the figures that he had been given, but we’d like to see a retraction and an apology.”

The problem arose because the figures quoted by Mr Timms included results from 604 small special schools. Small primaries were thus shown to be 20 percentage points adrift from larger schools in English, maths and science.

The DFES was aware of this in February but suggested that the mixed-age classes often found in such primary schools had contributed to the poor results.

The test scores of very small schools are not published, as it might be possible to identify the results of individual children. These schools therefore rely on word-of-mouth reputation. But as they are expensive to run - costs can be 50 per cent higher than those of an average-sized school - they are frequently under threat.

In England, 25 small schools have closed since September 1999, and a further 68 have disappeared through amalgamations.

After Stephen Timms’s statement in the Commons NASS pressed the department to re-issue the figures and separate the results for special schools. Although it has reworked the statistics the DFES has confirmed it will not apologise for the earlier misunderstanding.

“The figures were not inaccurate,” a DFES spokesperson maintained. “And there was certainly no intent to damage the reputation of small schools. Without prior knowledge of the context of the enquiry the question was answered honestly and straightforwardly at the time.” Mr Timms gave the original statistics in response to a question from Tory MP Mark Hoban about the relationship between the size of primary rolls and standards.